feat(i18n): add internationalization with i18next and expo-localization

2026-08-08 10:09:30 +02:00
parent 408a2fa10c
commit 9946e78858
81 changed files with 1820 additions and 125 deletions
@@ -1,21 +1,29 @@
 import "./global.css";
+import "./src/i18n";
 import { StatusBar } from "expo-status-bar";
 import { NavigationContainer } from "@react-navigation/native";
 import { RootNavigator } from "./src/navigation/RootNavigator";
 import { DatabaseProvider } from "./src/providers/DatabaseProvider";
 import { SettingsProvider } from "./src/providers/WatchProvider";
 import { useWatchWorkoutSync } from "./src/features/watch-connectivity/hooks/useWatchWorkoutSync";
+import { useSystemLanguageListener } from "./src/i18n";

 function WatchSync() {
  useWatchWorkoutSync();
  return null;
 }

+function SystemLanguageListener() {
+  useSystemLanguageListener();
+  return null;
+}
+
 export default function App() {
  return (
    <DatabaseProvider>
      <SettingsProvider>
        <NavigationContainer>
+          <SystemLanguageListener />
          <WatchSync />
          <RootNavigator />
          <StatusBar style="light" />
@@ -33,7 +33,10 @@
    },
    "plugins": [
      "expo-sqlite",
-      "@bacons/apple-targets"
+      "@bacons/apple-targets",
+      ["expo-localization", {
+        "supportedLocales": ["en", "nl", "de", "fr", "it", "es", "pl", "pt", "dk"]
+      }]
    ],
    "extra": {
      "eas": {
@@ -17,11 +17,14 @@
        "@tailwindcss/postcss": "^4.3.3",
        "drizzle-orm": "^0.45.2",
        "expo": "~57.0.10",
+        "expo-localization": "~57.0.1",
        "expo-sqlite": "~57.0.1",
        "expo-status-bar": "~57.0.1",
        "expo-system-ui": "~57.0.2",
+        "i18next": "^26.3.6",
        "nativewind": "^5.0.0-preview.4",
        "react": "19.2.3",
+        "react-i18next": "^17.0.11",
        "react-native": "0.86.2",
        "react-native-css": "^3.0.7",
        "react-native-gesture-handler": "~2.32.0",
@@ -5186,6 +5189,19 @@
        "react-native": "*"
      }
    },
+    "node_modules/expo-localization": {
+      "version": "57.0.1",
+      "resolved": "https://registry.npmjs.org/expo-localization/-/expo-localization-57.0.1.tgz",
+      "integrity": "sha512-8Ffl4UTbOsQeGT0v5fxMbyPHyPMPnhSPDFQJa8p9rjJrthFoAtNi+fL6Ssmrvf1/7dmPq1mVY52MEt0TMEfgjA==",
+      "license": "MIT",
+      "dependencies": {
+        "rtl-detect": "^1.0.2"
+      },
+      "peerDependencies": {
+        "expo": "*",
+        "react": "*"
+      }
+    },
    "node_modules/expo-modules-autolinking": {
      "version": "57.0.9",
      "resolved": "https://registry.npmjs.org/expo-modules-autolinking/-/expo-modules-autolinking-57.0.9.tgz",
@@ -6051,6 +6067,15 @@
      "integrity": "sha512-JNAzZcXrCt42VGLuYz0zfAzDfAvJWW6AfYlDBQyDV5DClI2m5sAmK+OIO7s59XfsRsWHp02jAJrRadPRGTt6SQ==",
      "license": "ISC"
    },
+    "node_modules/html-parse-stringify": {
+      "version": "4.0.1",
+      "resolved": "https://registry.npmjs.org/html-parse-stringify/-/html-parse-stringify-4.0.1.tgz",
+      "integrity": "sha512-0zHsZJrK7S3K2aucXWL6ycoYJ/iNtIcFHC/nYQgFklPtrv5LpJctIiSCroWZWeuoXvuyFdzp6KzjJQ+OT5MfFw==",
+      "license": "MIT",
+      "funding": {
+        "url": "https://locize.com"
+      }
+    },
    "node_modules/http-errors": {
      "version": "2.0.1",
      "resolved": "https://registry.npmjs.org/http-errors/-/http-errors-2.0.1.tgz",
@@ -6093,6 +6118,34 @@
        "node": ">= 14"
      }
    },
+    "node_modules/i18next": {
+      "version": "26.3.6",
+      "resolved": "https://registry.npmjs.org/i18next/-/i18next-26.3.6.tgz",
+      "integrity": "sha512-Bu5Z2nAXgfVyM8xvW3jk9EKRIuX37PudsrBViThNFx7CR7aaYTpP01cxNB/E4c4UUzTDiAZRstEhsRfPOL/8xA==",
+      "funding": [
+        {
+          "type": "individual",
+          "url": "https://www.locize.com/i18next"
+        },
+        {
+          "type": "individual",
+          "url": "https://www.i18next.com/how-to/faq#i18next-is-awesome.-how-can-i-support-the-project"
+        },
+        {
+          "type": "individual",
+          "url": "https://www.locize.com"
+        }
+      ],
+      "license": "MIT",
+      "peerDependencies": {
+        "typescript": "^5 || ^6 || ^7"
+      },
+      "peerDependenciesMeta": {
+        "typescript": {
+          "optional": true
+        }
+      }
+    },
    "node_modules/ignore": {
      "version": "5.3.2",
      "resolved": "https://registry.npmjs.org/ignore/-/ignore-5.3.2.tgz",
@@ -7881,6 +7934,33 @@
        "react": ">=17.0.0"
      }
    },
+    "node_modules/react-i18next": {
+      "version": "17.0.11",
+      "resolved": "https://registry.npmjs.org/react-i18next/-/react-i18next-17.0.11.tgz",
+      "integrity": "sha512-cDtkXgxjuFTWUH6V+aQn1Ve5vDiUztCNPWW5GtSHDccsgRXO1nE6QFWCEmc1KAutrb3OUv87wFShJL5RhUwPXg==",
+      "license": "MIT",
+      "dependencies": {
+        "@babel/runtime": "^7.29.2",
+        "html-parse-stringify": "^4.0.1",
+        "use-sync-external-store": "^1.6.0"
+      },
+      "peerDependencies": {
+        "i18next": ">= 26.2.0",
+        "react": ">= 16.8.0",
+        "typescript": "^5 || ^6 || ^7"
+      },
+      "peerDependenciesMeta": {
+        "react-dom": {
+          "optional": true
+        },
+        "react-native": {
+          "optional": true
+        },
+        "typescript": {
+          "optional": true
+        }
+      }
+    },
    "node_modules/react-is": {
      "version": "18.3.1",
      "resolved": "https://registry.npmjs.org/react-is/-/react-is-18.3.1.tgz",
@@ -8248,6 +8328,12 @@
        "node": ">=4"
      }
    },
+    "node_modules/rtl-detect": {
+      "version": "1.1.2",
+      "resolved": "https://registry.npmjs.org/rtl-detect/-/rtl-detect-1.1.2.tgz",
+      "integrity": "sha512-PGMBq03+TTG/p/cRB7HCLKJ1MgDIi07+QU1faSjiYRfmY5UsAttV9Hs08jDAHVwcOwmVLcSJkpwyfXszVjWfIQ==",
+      "license": "BSD-3-Clause"
+    },
    "node_modules/safe-buffer": {
      "version": "5.2.1",
      "resolved": "https://registry.npmjs.org/safe-buffer/-/safe-buffer-5.2.1.tgz",
@@ -11,11 +11,14 @@
    "@tailwindcss/postcss": "^4.3.3",
    "drizzle-orm": "^0.45.2",
    "expo": "~57.0.10",
+    "expo-localization": "~57.0.1",
    "expo-sqlite": "~57.0.1",
    "expo-status-bar": "~57.0.1",
    "expo-system-ui": "~57.0.2",
+    "i18next": "^26.3.6",
    "nativewind": "^5.0.0-preview.4",
    "react": "19.2.3",
+    "react-i18next": "^17.0.11",
    "react-native": "0.86.2",
    "react-native-css": "^3.0.7",
    "react-native-gesture-handler": "~2.32.0",
@@ -5,9 +5,10 @@ import { PanGestureHandler, State } from "react-native-gesture-handler";
 type SwipeableRowProps = {
  children: React.ReactNode;
  onDelete: () => void;
+  deleteLabel?: string;
 };

-export function SwipeableRow({ children, onDelete }: SwipeableRowProps) {
+export function SwipeableRow({ children, onDelete, deleteLabel = "Delete" }: SwipeableRowProps) {
  const translateX = useRef(new Animated.Value(0)).current;
  const lastOffset = useRef(0);

@@ -21,14 +22,12 @@ export function SwipeableRow({ children, onDelete }: SwipeableRowProps) {
      const newOffset = lastOffset.current + translationX;

      if (newOffset < -80) {
-        // Swiped left enough — show delete
        Animated.spring(translateX, {
          toValue: -80,
          useNativeDriver: true,
        }).start();
        lastOffset.current = -80;
      } else {
-        // Snap back
        Animated.spring(translateX, {
          toValue: 0,
          useNativeDriver: true,
@@ -52,7 +51,7 @@ export function SwipeableRow({ children, onDelete }: SwipeableRowProps) {
    <View style={styles.container}>
      <View style={styles.deleteBackground}>
        <Pressable onPress={handleDelete} style={styles.deleteButton}>
-          <Text style={styles.deleteText}>Delete</Text>
+          <Text style={styles.deleteText}>{deleteLabel}</Text>
        </Pressable>
      </View>
      <PanGestureHandler
@@ -1,5 +1,6 @@
 import { useEffect, useState } from "react";
 import { View, Text, Pressable } from "react-native";
+import { useTranslation } from "react-i18next";
 import { useNavigation, useRoute } from "@react-navigation/native";
 import type { NativeStackNavigationProp } from "@react-navigation/native-stack";
 import type { RootStackParamList } from "@navigation/types";
@@ -9,6 +10,8 @@ import { formatTime } from "@utils/formatTime";
 import { formatDistance } from "@utils/formatDistance";

 export function PostSwimScreen() {
+  const { t } = useTranslation("active-workout");
+  const { t: tc } = useTranslation("common");
  const navigation = useNavigation<NativeStackNavigationProp<RootStackParamList>>();
  const route = useRoute<RouteProp<RootStackParamList, "PostSwim">>();
  const [summary, setSummary] = useState<{
@@ -46,38 +49,38 @@ export function PostSwimScreen() {
    <View className="flex-1 bg-white p-4">
      <View className="items-center mb-8">
        <Text className="text-3xl mb-2">🏊</Text>
-        <Text className="text-2xl font-bold text-slate-900 mb-1">Swim Complete!</Text>
-        <Text className="text-slate-500">Great job getting in the water</Text>
+        <Text className="text-2xl font-bold text-slate-900 mb-1">{t("swimComplete")}</Text>
+        <Text className="text-slate-500">{t("greatJob")}</Text>
      </View>

      {summary ? (
        <View className="gap-3 mb-8">
          <View className="bg-sky-50 rounded-2xl p-5 flex-row justify-between items-center">
-            <Text className="text-slate-600">Distance</Text>
+            <Text className="text-slate-600">{tc("distance")}</Text>
            <Text className="text-xl font-bold text-sky-600">
              {formatDistance(summary.distance)}
            </Text>
          </View>
          <View className="bg-sky-50 rounded-2xl p-5 flex-row justify-between items-center">
-            <Text className="text-slate-600">Duration</Text>
+            <Text className="text-slate-600">{tc("duration")}</Text>
            <Text className="text-xl font-bold text-sky-600">
              {formatTime(summary.duration)}
            </Text>
          </View>
          <View className="bg-sky-50 rounded-2xl p-5 flex-row justify-between items-center">
-            <Text className="text-slate-600">Laps</Text>
+            <Text className="text-slate-600">{tc("laps")}</Text>
            <Text className="text-xl font-bold text-sky-600">{summary.laps}</Text>
          </View>
          {summary.avgSwolf && (
            <View className="bg-sky-50 rounded-2xl p-5 flex-row justify-between items-center">
-              <Text className="text-slate-600">Avg SWOLF</Text>
+              <Text className="text-slate-600">{tc("avgSwolf")}</Text>
              <Text className="text-xl font-bold text-sky-600">{summary.avgSwolf}</Text>
            </View>
          )}
        </View>
      ) : (
        <View className="py-8 items-center">
-          <Text className="text-slate-400">Loading summary...</Text>
+          <Text className="text-slate-400">{t("loadingSummary")}</Text>
        </View>
      )}

@@ -85,7 +88,7 @@ export function PostSwimScreen() {
        onPress={() => navigation.popToTop()}
        className="bg-slate-900 rounded-2xl py-4 items-center"
      >
-        <Text className="text-white font-bold text-lg">Done</Text>
+        <Text className="text-white font-bold text-lg">{tc("done")}</Text>
      </Pressable>
    </View>
  );
@@ -1,5 +1,6 @@
 import { useEffect, useState } from "react";
 import { View, Text, Pressable, ActivityIndicator } from "react-native";
+import { useTranslation } from "react-i18next";
 import { useNavigation, useRoute } from "@react-navigation/native";
 import type { NativeStackNavigationProp } from "@react-navigation/native-stack";
 import type { RootStackParamList } from "@navigation/types";
@@ -20,6 +21,8 @@ type WorkoutWithSets = {
 };

 export function PreSwimScreen() {
+  const { t } = useTranslation("active-workout");
+  const { t: tc } = useTranslation("common");
  const navigation = useNavigation<NativeStackNavigationProp<RootStackParamList>>();
  const route = useRoute<RouteProp<RootStackParamList, "PreSwim">>();
  const [workout, setWorkout] = useState<WorkoutWithSets | null>(null);
@@ -72,16 +75,16 @@ export function PreSwimScreen() {
      <View className="flex-1 bg-white p-4 items-center justify-center">
        <View className="bg-green-50 rounded-2xl p-6 items-center mb-6 w-full">
          <Text className="text-4xl mb-3">⌚</Text>
-          <Text className="text-xl font-bold text-green-800 mb-2">Workout sent to Watch!</Text>
+          <Text className="text-xl font-bold text-green-800 mb-2">{t("workoutSentToWatch")}</Text>
          <Text className="text-green-600 text-center">
-            Open the SwimBuddy app on your Apple Watch to start tracking.
+            {t("openWatchApp")}
          </Text>
        </View>
        <Pressable
          onPress={() => navigation.popToTop()}
          className="bg-slate-900 rounded-2xl py-4 items-center w-full"
        >
-          <Text className="text-white font-bold text-lg">Done</Text>
+          <Text className="text-white font-bold text-lg">{tc("done")}</Text>
        </Pressable>
      </View>
    );
@@ -92,16 +95,16 @@ export function PreSwimScreen() {
      <View className="flex-1 bg-white p-4 items-center justify-center">
        <View className="bg-red-50 rounded-2xl p-6 items-center mb-6 w-full">
          <Text className="text-4xl mb-3">⚠️</Text>
-          <Text className="text-xl font-bold text-red-800 mb-2">Failed to send</Text>
+          <Text className="text-xl font-bold text-red-800 mb-2">{t("failedToSend")}</Text>
          <Text className="text-red-600 text-center">
-            Could not send workout to Watch. Starting without Watch instead.
+            {t("couldNotSend")}
          </Text>
        </View>
        <Pressable
          onPress={() => navigation.navigate("PostSwim", { workoutId: route.params.workoutId })}
          className="bg-sky-500 rounded-2xl py-4 items-center w-full"
        >
-          <Text className="text-white font-bold text-lg">Start Without Watch</Text>
+          <Text className="text-white font-bold text-lg">{t("startWithoutWatch")}</Text>
        </Pressable>
      </View>
    );
@@ -111,16 +114,16 @@ export function PreSwimScreen() {
    <View className="flex-1 bg-white p-4">
      <View className="items-center mb-6">
        <Text className="text-2xl font-bold text-slate-900 mb-1">
-          {workout.name || "Workout"}
+          {workout.name || tc("workout")}
        </Text>
        <Text className="text-slate-500">
-          {formatDistance(workout.totalDistance ?? 0)} · {workout.poolLength}m pool
+          {formatDistance(workout.totalDistance ?? 0)} · {tc("pool", { length: workout.poolLength })}
        </Text>
      </View>

      <View className="bg-sky-50 rounded-2xl p-4 mb-4 border border-sky-100">
        <Text className="text-xs font-semibold text-sky-700 mb-3 uppercase tracking-wide">
-          Sets
+          {tc("sets")}
        </Text>
        {workout.sets.map((set, i) => (
          <View
@@ -132,7 +135,7 @@ export function PreSwimScreen() {
                className="w-3 h-3 rounded-full"
                style={{ backgroundColor: STROKE_COLORS[set.stroke] ?? "#94a3b8" }}
              />
-              <Text className="text-slate-700 font-medium">{set.stroke}</Text>
+              <Text className="text-slate-700 font-medium">{tc(`stroke.${set.stroke.toLowerCase()}`)}</Text>
            </View>
            <Text className="text-slate-600">
              {set.repCount}×{set.distancePerRep}m
@@ -143,9 +146,9 @@ export function PreSwimScreen() {

      <View className="bg-slate-50 rounded-2xl p-4 mb-6">
        <View className="flex-row justify-between mb-2">
-          <Text className="text-slate-500">Rest</Text>
+          <Text className="text-slate-500">{t("rest")}</Text>
          <Text className="text-slate-900 font-medium">
-            {workout.sets[0]?.restDuration ?? 0}s between sets
+            {t("betweenSets", { duration: workout.sets[0]?.restDuration ?? 0 })}
          </Text>
        </View>
      </View>
@@ -158,12 +161,12 @@ export function PreSwimScreen() {
        />
        <Text className="text-sm text-slate-600">
          {isReady
-            ? "Apple Watch ready"
+            ? t("watchStatus.ready")
            : isPaired
              ? isInstalled
-                ? "Watch paired but not in range"
-                : "Watch paired, app not installed"
-              : "No Watch paired"}
+                ? t("watchStatus.pairedNotInRange")
+                : t("watchStatus.pairedNotInstalled")
+              : t("watchStatus.noWatch")}
        </Text>
      </View>

@@ -178,15 +181,15 @@ export function PreSwimScreen() {
          <ActivityIndicator color="#fff" />
        ) : (
          <Text className="text-white font-bold text-lg">
-            {isReady ? "Send to Watch & Start" : "Start Without Watch"}
+            {isReady ? t("sendToWatchAndStart") : t("startWithoutWatch")}
          </Text>
        )}
      </Pressable>

      <Text className="text-slate-400 text-xs text-center mt-3">
        {isReady
-          ? "Workout will be synced to your Apple Watch"
-          : "Workout will be tracked on this device"}
+          ? t("syncToWatch")
+          : t("trackedOnDevice")}
      </Text>
    </View>
  );
@@ -1,5 +1,6 @@
 import { useCallback, useState } from "react";
 import { View, Text, Pressable, FlatList, Alert } from "react-native";
+import { useTranslation } from "react-i18next";
 import { useNavigation } from "@react-navigation/native";
 import { useFocusEffect } from "@react-navigation/native";
 import type { NativeStackNavigationProp } from "@react-navigation/native-stack";
@@ -20,6 +21,8 @@ type WorkoutRow = {
 };

 export function HistoryScreen() {
+  const { t } = useTranslation("history");
+  const { t: tc } = useTranslation("common");
  const navigation = useNavigation<NativeStackNavigationProp<HistoryStackParamList>>();
  const [workouts, setWorkouts] = useState<WorkoutRow[]>([]);
  const [refreshing, setRefreshing] = useState(false);
@@ -42,10 +45,10 @@ export function HistoryScreen() {
  };

  const onDelete = (id: string) => {
-    Alert.alert("Delete Workout", "Are you sure?", [
-      { text: "Cancel", style: "cancel" },
+    Alert.alert(tc("alert.deleteWorkout"), tc("alert.areYouSure"), [
+      { text: tc("cancel"), style: "cancel" },
      {
-        text: "Delete",
+        text: tc("delete"),
        style: "destructive",
        onPress: async () => {
          await deleteWorkout(id);
@@ -74,7 +77,7 @@ export function HistoryScreen() {
        onRefresh={onRefresh}
        ListEmptyComponent={
          <View className="py-12 items-center">
-            <Text className="text-slate-400 text-lg">No completed workouts yet</Text>
+            <Text className="text-slate-400 text-lg">{t("noCompletedYet")}</Text>
          </View>
        }
        renderItem={({ item: [date, rows] }) => (
@@ -83,7 +86,7 @@ export function HistoryScreen() {
              {date}
            </Text>
            {rows.map((w) => (
-              <SwipeableRow key={w.id} onDelete={() => onDelete(w.id)}>
+              <SwipeableRow key={w.id} onDelete={() => onDelete(w.id)} deleteLabel={tc("delete")}>
                <Pressable
                  onPress={() => navigation.navigate("SessionDetail", { sessionId: w.id })}
                  className="p-4"
@@ -91,12 +94,12 @@ export function HistoryScreen() {
                  <View className="flex-row justify-between items-center">
                    <View>
                      <Text className="font-semibold text-slate-900">
-                        {w.name || "Swim Session"}
+                        {w.name || tc("swimSession")}
                      </Text>
                      <Text className="text-slate-500 text-sm">
                        {formatDistance(w.totalDistance ?? 0)}
                        {w.totalDuration ? ` · ${formatTime(w.totalDuration)}` : ""}
-                        {w.calories ? ` · ${Math.round(w.calories)} kcal` : ""}
+                        {w.calories ? ` · ${tc("kcal", { count: Math.round(w.calories) })}` : ""}
                      </Text>
                    </View>
                    <Text className="text-slate-400 text-xs">
@@ -1,5 +1,6 @@
 import { useEffect, useState } from "react";
 import { View, Text, ScrollView, Pressable, Alert } from "react-native";
+import { useTranslation } from "react-i18next";
 import { useNavigation } from "@react-navigation/native";
 import type { HistoryStackProps } from "@navigation/types";
 import { getWorkoutWithSets, deleteWorkout } from "@db/operations";
@@ -35,6 +36,8 @@ type WorkoutDetail = {
 };

 export function SessionDetailScreen({ route }: HistoryStackProps<"SessionDetail">) {
+  const { t } = useTranslation("history");
+  const { t: tc } = useTranslation("common");
  const navigation = useNavigation();
  const [workout, setWorkout] = useState<WorkoutDetail | null>(null);

@@ -48,10 +51,10 @@ export function SessionDetailScreen({ route }: HistoryStackProps<"SessionDetail"
  };

  const handleDelete = () => {
-    Alert.alert("Delete Workout", "Are you sure?", [
-      { text: "Cancel", style: "cancel" },
+    Alert.alert(tc("alert.deleteWorkout"), tc("alert.areYouSure"), [
+      { text: tc("cancel"), style: "cancel" },
      {
-        text: "Delete",
+        text: tc("delete"),
        style: "destructive",
        onPress: async () => {
          await deleteWorkout(route.params.sessionId);
@@ -64,7 +67,7 @@ export function SessionDetailScreen({ route }: HistoryStackProps<"SessionDetail"
  if (!workout) {
    return (
      <View className="flex-1 bg-white items-center justify-center">
-        <Text className="text-slate-400">Loading...</Text>
+        <Text className="text-slate-400">{tc("loading")}</Text>
      </View>
    );
  }
@@ -81,7 +84,7 @@ export function SessionDetailScreen({ route }: HistoryStackProps<"SessionDetail"
      <View className="flex-row justify-between items-start mb-6">
        <View className="flex-1">
          <Text className="text-2xl font-bold text-slate-900 mb-1">
-            {workout.name || "Swim Session"}
+            {workout.name || tc("swimSession")}
          </Text>
          <Text className="text-slate-500">
            {new Date(workout.startedAt).toLocaleDateString()}
@@ -100,13 +103,13 @@ export function SessionDetailScreen({ route }: HistoryStackProps<"SessionDetail"
          <Text className="text-2xl font-bold text-sky-600">
            {formatDistance(workout.totalDistance ?? 0)}
          </Text>
-          <Text className="text-xs text-slate-500 mt-1">Distance</Text>
+          <Text className="text-xs text-slate-500 mt-1">{tc("distance")}</Text>
        </View>
        <View className="flex-1 bg-sky-50 rounded-2xl p-4 items-center">
          <Text className="text-2xl font-bold text-sky-600">
            {formatTime(workout.totalDuration ?? 0)}
          </Text>
-          <Text className="text-xs text-slate-500 mt-1">Duration</Text>
+          <Text className="text-xs text-slate-500 mt-1">{tc("duration")}</Text>
        </View>
        {workout.calories && (
          <View className="flex-1 bg-sky-50 rounded-2xl p-4 items-center">
@@ -120,13 +123,13 @@ export function SessionDetailScreen({ route }: HistoryStackProps<"SessionDetail"

      {avgSwolf && (
        <View className="bg-slate-50 rounded-2xl p-4 mb-4">
-          <Text className="text-sm font-semibold text-slate-700">Avg SWOLF</Text>
+          <Text className="text-sm font-semibold text-slate-700">{tc("avgSwolf")}</Text>
          <Text className="text-xl font-bold text-slate-900">{avgSwolf}</Text>
        </View>
      )}

      <Text className="text-sm font-semibold text-slate-500 uppercase tracking-wide mb-2">
-        Sets
+        {tc("sets")}
      </Text>
      {workout.sets.map((set, i) => (
        <View
@@ -138,7 +141,7 @@ export function SessionDetailScreen({ route }: HistoryStackProps<"SessionDetail"
              className="w-3 h-3 rounded-full"
              style={{ backgroundColor: STROKE_COLORS[set.stroke] ?? "#94a3b8" }}
            />
-            <Text className="text-slate-700 font-medium">{set.stroke}</Text>
+            <Text className="text-slate-700 font-medium">{tc(`stroke.${set.stroke.toLowerCase()}`)}</Text>
          </View>
          <Text className="text-slate-600">
            {set.repCount}×{set.distancePerRep}m
@@ -149,7 +152,7 @@ export function SessionDetailScreen({ route }: HistoryStackProps<"SessionDetail"
      {workout.laps.length > 0 && (
        <>
          <Text className="text-sm font-semibold text-slate-500 uppercase tracking-wide mt-6 mb-2">
-            Laps
+            {tc("laps")}
          </Text>
          {workout.laps.map((lap, i) => (
            <View
@@ -157,7 +160,7 @@ export function SessionDetailScreen({ route }: HistoryStackProps<"SessionDetail"
              className="flex-row justify-between py-2 border-b border-slate-100"
            >
              <Text className="text-slate-600">
-                Lap {i + 1} · {lap.distance}m
+                {t("lap", { number: i + 1 })} · {lap.distance}m
              </Text>
              <Text className="text-slate-600 font-medium">
                {formatTime(lap.duration)}
@@ -1,5 +1,6 @@
 import { useEffect, useState } from "react";
 import { View, Text, ScrollView } from "react-native";
+import { useTranslation } from "react-i18next";
 import { getWeeklyStats, getTotalStats, getPersonalBests } from "@db/operations";
 import { formatDistance } from "@utils/formatDistance";
 import { formatTime } from "@utils/formatTime";
@@ -24,6 +25,8 @@ type PersonalBest = {
 };

 export function StatsScreen() {
+  const { t } = useTranslation("history");
+  const { t: tc } = useTranslation("common");
  const [weekly, setWeekly] = useState<WeeklyStats | null>(null);
  const [total, setTotal] = useState<TotalStats | null>(null);
  const [bests, setBests] = useState<PersonalBest[]>([]);
@@ -45,79 +48,79 @@ export function StatsScreen() {

  return (
    <ScrollView className="flex-1 bg-white p-4">
-      <Text className="text-2xl font-bold text-slate-900 mb-6">Statistics</Text>
+      <Text className="text-2xl font-bold text-slate-900 mb-6">{t("statistics")}</Text>

      <Text className="text-xs font-semibold text-slate-500 uppercase tracking-wide mb-2">
-        This Week
+        {t("thisWeek")}
      </Text>
      <View className="bg-sky-50 rounded-2xl p-4 mb-6">
        {weekly ? (
          <View className="flex-row justify-between">
            <View className="items-center flex-1">
              <Text className="text-2xl font-bold text-sky-600">{weekly.count}</Text>
-              <Text className="text-xs text-slate-500">Workouts</Text>
+              <Text className="text-xs text-slate-500">{tc("workouts")}</Text>
            </View>
            <View className="items-center flex-1">
              <Text className="text-2xl font-bold text-sky-600">
                {formatDistance(weekly.totalDistance)}
              </Text>
-              <Text className="text-xs text-slate-500">Distance</Text>
+              <Text className="text-xs text-slate-500">{tc("distance")}</Text>
            </View>
            <View className="items-center flex-1">
              <Text className="text-2xl font-bold text-sky-600">
                {formatTime(weekly.totalDuration)}
              </Text>
-              <Text className="text-xs text-slate-500">Duration</Text>
+              <Text className="text-xs text-slate-500">{tc("duration")}</Text>
            </View>
          </View>
        ) : (
-          <Text className="text-slate-400 text-center py-4">No data yet</Text>
+          <Text className="text-slate-400 text-center py-4">{t("noDataYet")}</Text>
        )}
      </View>

      <Text className="text-xs font-semibold text-slate-500 uppercase tracking-wide mb-2">
-        All Time
+        {t("allTime")}
      </Text>
      <View className="bg-slate-50 rounded-2xl p-4 mb-6">
        {total ? (
          <View className="flex-row justify-between">
            <View className="items-center flex-1">
              <Text className="text-2xl font-bold text-slate-700">{total.totalWorkouts}</Text>
-              <Text className="text-xs text-slate-500">Workouts</Text>
+              <Text className="text-xs text-slate-500">{tc("workouts")}</Text>
            </View>
            <View className="items-center flex-1">
              <Text className="text-2xl font-bold text-slate-700">
                {formatDistance(total.totalDistance)}
              </Text>
-              <Text className="text-xs text-slate-500">Distance</Text>
+              <Text className="text-xs text-slate-500">{tc("distance")}</Text>
            </View>
            <View className="items-center flex-1">
              <Text className="text-2xl font-bold text-slate-700">
                {formatTime(total.totalDuration)}
              </Text>
-              <Text className="text-xs text-slate-500">Duration</Text>
+              <Text className="text-xs text-slate-500">{tc("duration")}</Text>
            </View>
          </View>
        ) : (
-          <Text className="text-slate-400 text-center py-4">No data yet</Text>
+          <Text className="text-slate-400 text-center py-4">{t("noDataYet")}</Text>
        )}
      </View>

      {bests.length > 0 && (
        <>
          <Text className="text-xs font-semibold text-slate-500 uppercase tracking-wide mb-2">
-            Personal Bests
+            {t("personalBests")}
          </Text>
          {bests.map((best) => (
            <View
              key={best.distance}
              className="bg-green-50 rounded-2xl p-4 mb-2 flex-row justify-between items-center"
            >
-              <Text className="text-green-700 font-medium">{best.distance}m</Text>
+              <Text className="text-green-700 font-medium">{tc("meter", { count: best.distance })}</Text>
              <View className="items-end">
                <Text className="text-green-800 font-bold">{formatTime(best.bestTime)}</Text>
                {best.bestSwolf && (
-                  <Text className="text-green-600 text-xs">SWOLF: {best.bestSwolf}</Text>
+                  <Text className="text-green-600 text-xs">{t("swolf", { value: best.bestSwolf })}</Text>
                )}
              </View>
            </View>
@@ -0,0 +1,48 @@
+import { View, Text, Pressable } from "react-native";
+import { useTranslation } from "react-i18next";
+import { useSettings } from "../../../providers/WatchProvider";
+import { LANGUAGES } from "@i18n/index";
+
+export function LanguagePicker() {
+  const { t } = useTranslation("settings");
+  const { language, setLanguage } = useSettings();
+
+  return (
+    <View className="mb-6">
+      <Text className="text-sm font-medium text-slate-500 mb-2">{t("language")}</Text>
+      <View className="flex-row flex-wrap gap-2">
+        <Pressable
+          onPress={() => setLanguage("system")}
+          className={`px-3 py-2 rounded-xl ${
+            language === "system" ? "bg-sky-500" : "bg-slate-100"
+          }`}
+        >
+          <Text
+            className={`text-sm font-medium ${
+              language === "system" ? "text-white" : "text-slate-600"
+            }`}
+          >
+            {t("systemLanguage")}
+          </Text>
+        </Pressable>
+        {LANGUAGES.map((lang) => (
+          <Pressable
+            key={lang.code}
+            onPress={() => setLanguage(lang.code)}
+            className={`px-3 py-2 rounded-xl ${
+              language === lang.code ? "bg-sky-500" : "bg-slate-100"
+            }`}
+          >
+            <Text
+              className={`text-sm font-medium ${
+                language === lang.code ? "text-white" : "text-slate-600"
+              }`}
+            >
+              {lang.label}
+            </Text>
+          </Pressable>
+        ))}
+      </View>
+    </View>
+  );
+}
@@ -1,15 +1,20 @@
 import { View, Text, Pressable } from "react-native";
+import { useTranslation } from "react-i18next";
 import { useSettings } from "../../../providers/WatchProvider";
+import { LanguagePicker } from "../components/LanguagePicker";

 export function SettingsScreen() {
+  const { t } = useTranslation("settings");
  const { poolLength, setPoolLength } = useSettings();

  return (
    <View className="flex-1 bg-white p-4">
-      <Text className="text-2xl font-bold text-slate-900 mb-6">Settings</Text>
+      <Text className="text-2xl font-bold text-slate-900 mb-6">{t("settings")}</Text>
+
+      <LanguagePicker />

      <View className="mb-6">
-        <Text className="text-sm font-medium text-slate-500 mb-2">Default Pool Length</Text>
+        <Text className="text-sm font-medium text-slate-500 mb-2">{t("defaultPoolLength")}</Text>
        <View className="flex-row gap-3">
          {[25, 50].map((len) => (
            <Pressable
@@ -32,7 +37,7 @@ export function SettingsScreen() {
      </View>

      <View className="border-t border-slate-200 pt-4 mt-2">
-        <Text className="text-sm text-slate-400">SwimBuddy v1.0.0</Text>
+        <Text className="text-sm text-slate-400">{t("version")}</Text>
      </View>
    </View>
  );
@@ -1,3 +1,4 @@
+import { useTranslation } from "react-i18next";
 import { View, Text, Pressable, FlatList, Alert } from "react-native";
 import { useNavigation } from "@react-navigation/native";
 import type { NativeStackNavigationProp } from "@react-navigation/native-stack";
@@ -5,13 +6,14 @@ import type { WorkoutStackParamList } from "@navigation/types";
 import { useTemplates } from "../hooks/useTemplates";

 export function TemplatesScreen() {
+  const { t } = useTranslation("common");
  const navigation = useNavigation<NativeStackNavigationProp<WorkoutStackParamList>>();
  const { templates, remove, toggleFavorite } = useTemplates();

  const handleDelete = (id: string, name: string) => {
-    Alert.alert("Delete Template", `Delete "${name}"?`, [
-      { text: "Cancel", style: "cancel" },
-      { text: "Delete", style: "destructive", onPress: () => remove(id) },
+    Alert.alert(t("alert.deleteTemplate"), t("alert.deleteConfirm", { name }), [
+      { text: t("cancel"), style: "cancel" },
+      { text: t("delete"), style: "destructive", onPress: () => remove(id) },
    ]);
  };

@@ -23,9 +25,9 @@ export function TemplatesScreen() {
        contentContainerClassName="p-4"
        ListEmptyComponent={
          <View className="py-12 items-center">
-            <Text className="text-slate-400 text-lg">No templates yet</Text>
+            <Text className="text-slate-400 text-lg">{t("alert.deleteTemplate")}</Text>
            <Text className="text-slate-400 text-sm mt-1">
-              Save a workout as a template to reuse it
+              {t("noTemplatesYet")}
            </Text>
          </View>
        }
@@ -38,7 +40,7 @@ export function TemplatesScreen() {
              <View className="flex-1">
                <Text className="font-semibold text-slate-900 text-base">{item.name}</Text>
                <Text className="text-slate-500 text-sm mt-1">
-                  {item.poolLength}m pool
+                  {t("pool", { length: item.poolLength })}
                </Text>
              </View>
              <View className="flex-row gap-2">
@@ -1,6 +1,7 @@
 import { useState, useCallback } from "react";
 import type { WorkoutSet, StrokeType, RestType } from "@types/workout";
 import { saveWorkout, saveTemplate } from "@db/operations";
+import i18n from "@i18n/index";

 const DEFAULT_SET: WorkoutSet = {
  stroke: "Freestyle",
@@ -33,7 +34,7 @@ export function useWorkoutBuilder(initialSets?: WorkoutSet[]) {
    async (poolLength: number, templateId?: string) => {
      setIsSaving(true);
      try {
-        const name = workoutName.trim() || `Workout ${new Date().toLocaleDateString()}`;
+        const name = workoutName.trim() || i18n.t("workout:untitledWorkout");
        const id = await saveWorkout(name, poolLength, sets, templateId);
        return id;
      } finally {
@@ -1,5 +1,6 @@
 import { useState } from "react";
 import { View, Text, TextInput, Pressable, ScrollView, Alert } from "react-native";
+import { useTranslation } from "react-i18next";
 import { useNavigation } from "@react-navigation/native";
 import type { NativeStackNavigationProp } from "@react-navigation/native-stack";
 import type { RootStackParamList } from "@navigation/types";
@@ -10,6 +11,8 @@ import type { StrokeType } from "@types/workout";
 const STROKES: StrokeType[] = ["Freestyle", "Backstroke", "Breaststroke", "Butterfly", "Mixed"];

 export function BuilderScreen() {
+  const { t } = useTranslation("workout");
+  const { t: tc } = useTranslation("common");
  const navigation = useNavigation<NativeStackNavigationProp<RootStackParamList>>();
  const { poolLength: defaultPoolLength } = useSettings();
  const [poolLength, setPoolLength] = useState(defaultPoolLength);
@@ -31,31 +34,31 @@ export function BuilderScreen() {
      navigation.navigate("PreSwim", { workoutId });
    } catch (e) {
      console.error("Failed to save workout:", e);
-      Alert.alert("Error", `Failed to save workout: ${e}`);
+      Alert.alert(tc("validation.error"), tc("validation.failedToSave", { error: String(e) }));
    }
  };

  return (
    <ScrollView className="flex-1 bg-white">
      <View className="p-4">
-        <Text className="text-2xl font-bold text-slate-900 mb-1">Build Workout</Text>
+        <Text className="text-2xl font-bold text-slate-900 mb-1">{t("buildWorkout")}</Text>
        <Text className="text-slate-500 mb-4">
-          {totalDistance}m total · {poolLength}m pool
+          {totalDistance}m total · {tc("pool", { length: poolLength })}
        </Text>

        <View className="mb-4">
-          <Text className="text-sm font-medium text-slate-500 mb-1">Workout Name</Text>
+          <Text className="text-sm font-medium text-slate-500 mb-1">{t("workoutName")}</Text>
          <TextInput
            value={workoutName}
            onChangeText={setWorkoutName}
-            placeholder="Morning Swim"
+            placeholder={t("placeholder.workoutName")}
            placeholderTextColor="#94a3b8"
            className="bg-slate-50 border border-slate-200 rounded-xl px-4 py-3 text-slate-900"
          />
        </View>

        <View className="mb-4">
-          <Text className="text-sm font-medium text-slate-500 mb-1">Pool Length</Text>
+          <Text className="text-sm font-medium text-slate-500 mb-1">{t("poolLength")}</Text>
          <View className="flex-row gap-2">
            {[25, 50].map((length) => (
              <Pressable
@@ -80,16 +83,16 @@ export function BuilderScreen() {
        {sets.map((set, index) => (
          <View key={index} className="bg-slate-50 rounded-2xl p-4 mb-3 border border-slate-200">
            <View className="flex-row justify-between items-center mb-3">
-              <Text className="font-semibold text-slate-700">Set {index + 1}</Text>
+              <Text className="font-semibold text-slate-700">{t("setNumber", { number: index + 1 })}</Text>
              {sets.length > 1 && (
                <Pressable onPress={() => removeSet(index)}>
-                  <Text className="text-red-500 text-sm font-medium">Remove</Text>
+                  <Text className="text-red-500 text-sm font-medium">{t("remove")}</Text>
                </Pressable>
              )}
            </View>

            <Text className="text-xs font-medium text-slate-500 mb-1.5 uppercase tracking-wide">
-              Stroke
+              {t("stroke")}
            </Text>
            <ScrollView horizontal showsHorizontalScrollIndicator={false} className="mb-3">
              {STROKES.map((stroke) => (
@@ -105,7 +108,7 @@ export function BuilderScreen() {
                      set.stroke === stroke ? "text-white" : "text-slate-600"
                    }`}
                  >
-                    {stroke}
+                    {tc(`stroke.${stroke.toLowerCase()}`)}
                  </Text>
                </Pressable>
              ))}
@@ -113,29 +116,29 @@ export function BuilderScreen() {

            <View className="flex-row gap-2">
              <View className="flex-1">
-                <Text className="text-xs font-medium text-slate-500 mb-1">Distance (m)</Text>
+                <Text className="text-xs font-medium text-slate-500 mb-1">{t("distanceM")}</Text>
                <TextInput
                  keyboardType="numeric"
                  value={String(set.distancePerRep)}
-                  onChangeText={(t) => updateSet(index, { distancePerRep: Number(t) || 0 })}
+                  onChangeText={(val) => updateSet(index, { distancePerRep: Number(val) || 0 })}
                  className="bg-white border border-slate-300 rounded-lg px-3 py-2 text-slate-900"
                />
              </View>
              <View className="flex-1">
-                <Text className="text-xs font-medium text-slate-500 mb-1">Reps</Text>
+                <Text className="text-xs font-medium text-slate-500 mb-1">{t("reps")}</Text>
                <TextInput
                  keyboardType="numeric"
                  value={String(set.repCount)}
-                  onChangeText={(t) => updateSet(index, { repCount: Number(t) || 1 })}
+                  onChangeText={(val) => updateSet(index, { repCount: Number(val) || 1 })}
                  className="bg-white border border-slate-300 rounded-lg px-3 py-2 text-slate-900"
                />
              </View>
              <View className="flex-1">
-                <Text className="text-xs font-medium text-slate-500 mb-1">Rest (s)</Text>
+                <Text className="text-xs font-medium text-slate-500 mb-1">{t("restS")}</Text>
                <TextInput
                  keyboardType="numeric"
                  value={String(set.restDuration)}
-                  onChangeText={(t) => updateSet(index, { restDuration: Number(t) || 0 })}
+                  onChangeText={(val) => updateSet(index, { restDuration: Number(val) || 0 })}
                  className="bg-white border border-slate-300 rounded-lg px-3 py-2 text-slate-900"
                />
              </View>
@@ -147,7 +150,7 @@ export function BuilderScreen() {
          onPress={addSet}
          className="bg-slate-100 rounded-2xl py-3 items-center mb-6 border border-slate-200"
        >
-          <Text className="text-sky-600 font-semibold">+ Add Set</Text>
+          <Text className="text-sky-600 font-semibold">{t("addSet")}</Text>
        </Pressable>

        <Pressable
@@ -156,7 +159,7 @@ export function BuilderScreen() {
          className={`rounded-2xl py-4 items-center mb-8 ${isSaving ? "bg-sky-300" : "bg-sky-500"}`}
        >
          <Text className="text-white font-bold text-lg">
-            {isSaving ? "Saving..." : "Start Swim"}
+            {isSaving ? tc("saving") : t("startSwim")}
          </Text>
        </Pressable>
      </View>
@@ -1,5 +1,6 @@
 import { useCallback, useState } from "react";
 import { View, Text, Pressable, FlatList, Alert } from "react-native";
+import { useTranslation } from "react-i18next";
 import { useNavigation } from "@react-navigation/native";
 import { useFocusEffect } from "@react-navigation/native";
 import type { NativeStackNavigationProp } from "@react-navigation/native-stack";
@@ -19,6 +20,8 @@ type WorkoutRow = {
 };

 export function WorkoutListScreen() {
+  const { t } = useTranslation("workout");
+  const { t: tc } = useTranslation("common");
  const navigation = useNavigation<NativeStackNavigationProp<WorkoutStackParamList>>();
  const [workouts, setWorkouts] = useState<WorkoutRow[]>([]);
  const [refreshing, setRefreshing] = useState(false);
@@ -41,10 +44,10 @@ export function WorkoutListScreen() {
  };

  const onDelete = (id: string) => {
-    Alert.alert("Delete Workout", "Are you sure?", [
-      { text: "Cancel", style: "cancel" },
+    Alert.alert(tc("alert.deleteWorkout"), tc("alert.areYouSure"), [
+      { text: tc("cancel"), style: "cancel" },
      {
-        text: "Delete",
+        text: tc("delete"),
        style: "destructive",
        onPress: async () => {
          await deleteWorkout(id);
@@ -61,7 +64,7 @@ export function WorkoutListScreen() {
          onPress={() => navigation.navigate("Builder")}
          className="bg-sky-500 rounded-2xl p-4 items-center mb-4"
        >
-          <Text className="text-white font-bold text-lg">+ New Workout</Text>
+          <Text className="text-white font-bold text-lg">{t("newWorkout")}</Text>
        </Pressable>
      </View>

@@ -73,12 +76,12 @@ export function WorkoutListScreen() {
        onRefresh={onRefresh}
        ListEmptyComponent={
          <View className="py-12 items-center">
-            <Text className="text-slate-400 text-lg">No workouts yet</Text>
-            <Text className="text-slate-400 text-sm mt-1">Tap "New Workout" to get started</Text>
+            <Text className="text-slate-400 text-lg">{t("noWorkoutsYet")}</Text>
+            <Text className="text-slate-400 text-sm mt-1">{t("tapNewWorkout")}</Text>
          </View>
        }
        renderItem={({ item }) => (
-          <SwipeableRow onDelete={() => onDelete(item.id)}>
+          <SwipeableRow onDelete={() => onDelete(item.id)} deleteLabel={tc("delete")}>
            <Pressable
              onPress={() => navigation.navigate("PreSwim", { workoutId: item.id })}
              className="p-4"
@@ -86,7 +89,7 @@ export function WorkoutListScreen() {
              <View className="flex-row justify-between items-start">
                <View className="flex-1">
                  <Text className="font-semibold text-slate-900 text-base">
-                    {item.name || "Untitled Workout"}
+                    {item.name || tc("untitledWorkout")}
                  </Text>
                  <Text className="text-slate-500 text-sm mt-1">
                    {formatDistance(item.totalDistance ?? 0)}
@@ -98,7 +101,7 @@ export function WorkoutListScreen() {
                </View>
                {item.finishedAt && (
                  <View className="bg-green-100 rounded-full px-2 py-0.5">
-                    <Text className="text-green-700 text-xs font-medium">Done</Text>
+                    <Text className="text-green-700 text-xs font-medium">{tc("done")}</Text>
                  </View>
                )}
              </View>
@@ -0,0 +1,21 @@
+{
+  "workoutSentToWatch": "Workout an Watch gesendet!",
+  "openWatchApp": "Öffne die SwimBuddy-App auf deiner Apple Watch, um mit der Verfolgung zu beginnen.",
+  "failedToSend": "Senden fehlgeschlagen",
+  "couldNotSend": "Workout konnte nicht an Watch gesendet werden. Starte ohne Watch.",
+  "startWithoutWatch": "Ohne Watch starten",
+  "sendToWatchAndStart": "An Watch senden & starten",
+  "syncToWatch": "Workout wird mit deiner Apple Watch synchronisiert",
+  "trackedOnDevice": "Workout wird auf diesem Gerät verfolgt",
+  "rest": "Pause",
+  "betweenSets": "{{duration}}s Pause zwischen Sets",
+  "swimComplete": "Schwimmen abgeschlossen!",
+  "greatJob": "Gut gemacht! Du bist heute ins Wasser gegangen!",
+  "loadingSummary": "Zusammenfassung laden...",
+  "watchStatus": {
+    "ready": "Apple Watch bereit",
+    "pairedNotInRange": "Watch gekoppelt, aber nicht in Reichweite",
+    "pairedNotInstalled": "Watch gekoppelt, App nicht installiert",
+    "noWatch": "Keine Watch gekoppelt"
+  }
+}
@@ -0,0 +1,43 @@
+{
+  "done": "Fertig",
+  "cancel": "Abbrechen",
+  "delete": "Löschen",
+  "start": "Starten",
+  "back": "Zurück",
+  "loading": "Laden...",
+  "error": "Fehler",
+  "save": "Speichern",
+  "saving": "Speichern...",
+  "yes": "Ja",
+  "no": "Nein",
+  "confirm": "Bestätigen",
+  "ok": "OK",
+  "distance": "Distanz",
+  "duration": "Dauer",
+  "workouts": "Workouts",
+  "sets": "Sets",
+  "laps": "Bahnen",
+  "avgSwolf": "Durchschn. SWOLF",
+  "pool": "{{length}}m Becken",
+  "untitledWorkout": "Unbenannter Workout",
+  "swimSession": "Schwimmsitzung",
+  "workout": "Workout",
+  "kcal": "{{count}} kcal",
+  "meter": "{{count}}m",
+  "kilometer": "{{count}}km",
+  "pace": "{{pace}}/100m",
+  "noPace": "--:--",
+  "stroke": {
+    "freestyle": "Freistil",
+    "backstroke": "Rücken",
+    "breaststroke": "Brust",
+    "butterfly": "Schmetterling",
+    "mixed": "Gemischt"
+  },
+  "alert": {
+    "deleteWorkout": "Workout löschen",
+    "deleteTemplate": "Vorlage löschen",
+    "areYouSure": "Bist du sicher?",
+    "deleteConfirm": "\"{{name}}\" löschen?"
+  }
+}
@@ -0,0 +1,10 @@
+{
+  "noCompletedYet": "Noch keine abgeschlossenen Workouts",
+  "lap": "Bahn {{number}}",
+  "statistics": "Statistiken",
+  "thisWeek": "Diese Woche",
+  "allTime": "Gesamtzeit",
+  "personalBests": "Persönliche Bestleistungen",
+  "noDataYet": "Noch keine Daten",
+  "swolf": "SWOLF: {{value}}"
+}
@@ -0,0 +1,12 @@
+{
+  "workouts": "Workouts",
+  "history": "Verlauf",
+  "settings": "Einstellungen",
+  "newWorkout": "Neues Workout",
+  "buildWorkout": "Workout erstellen",
+  "startSwim": "Schwimmen starten",
+  "readyToSwim": "Bereit zum Schwimmen",
+  "swimComplete": "Schwimmen abgeschlossen",
+  "session": "Sitzung",
+  "sessionDetail": "Sitzungsdetails"
+}
@@ -0,0 +1,7 @@
+{
+  "settings": "Einstellungen",
+  "defaultPoolLength": "Standard-Beckenlänge",
+  "language": "Sprache",
+  "systemLanguage": "Systemsprache",
+  "version": "SwimBuddy v1.0.0"
+}
@@ -0,0 +1,23 @@
+{
+  "workoutName": "Workout-Name",
+  "poolLength": "Beckenlänge",
+  "stroke": "Lage",
+  "distanceM": "Distanz (m)",
+  "reps": "Wiederholungen",
+  "restS": "Pause (s)",
+  "addSet": "+ Set hinzufügen",
+  "remove": "Entfernen",
+  "setNumber": "Set {{number}}",
+  "startSwim": "Schwimmen starten",
+  "newWorkout": "+ Neues Workout",
+  "noWorkoutsYet": "Noch keine Workouts",
+  "tapNewWorkout": "Tippe auf \"Neues Workout\" um zu beginnen",
+  "morningSwim": "Morgenschwimmen",
+  "placeholder": {
+    "workoutName": "Morgenschwimmen"
+  },
+  "validation": {
+    "error": "Fehler",
+    "failedToSave": "Workout konnte nicht gespeichert werden: {{error}}"
+  }
+}
@@ -0,0 +1,21 @@
+{
+  "workoutSentToWatch": "Træning sendt til Watch!",
+  "openWatchApp": "Åbn SwimBuddy-appen på din Apple Watch for at begynde sporing.",
+  "failedToSend": "Sendning mislykkedes",
+  "couldNotSend": "Kunne ikke sende træning til Watch. Starter uden Watch.",
+  "startWithoutWatch": "Start uden Watch",
+  "sendToWatchAndStart": "Send til Watch & start",
+  "syncToWatch": "Træningen synkroniseres med din Apple Watch",
+  "trackedOnDevice": "Træningen spores på denne enhed",
+  "rest": "Hvile",
+  "betweenSets": "{{duration}}s hvile mellem sæt",
+  "swimComplete": "Svømning fuldført!",
+  "greatJob": "Godt gået! Du var i vandet i dag!",
+  "loadingSummary": "Indlæser opsummering...",
+  "watchStatus": {
+    "ready": "Apple Watch klar",
+    "pairedNotInRange": "Watch parret, men ikke inden for rækkevidde",
+    "pairedNotInstalled": "Watch parret, app ikke installeret",
+    "noWatch": "Ingen Watch parret"
+  }
+}
@@ -0,0 +1,43 @@
+{
+  "done": "Færdig",
+  "cancel": "Annuller",
+  "delete": "Slet",
+  "start": "Start",
+  "back": "Tilbage",
+  "loading": "Indlæser...",
+  "error": "Fejl",
+  "save": "Gem",
+  "saving": "Gemmer...",
+  "yes": "Ja",
+  "no": "Nej",
+  "confirm": "Bekræft",
+  "ok": "OK",
+  "distance": "Distance",
+  "duration": "Varighed",
+  "workouts": "Træninger",
+  "sets": "Sæt",
+  "laps": "Baner",
+  "avgSwolf": "Gns. SWOLF",
+  "pool": "{{length}}m pool",
+  "untitledWorkout": "Unavngiven træning",
+  "swimSession": "Svømmesession",
+  "workout": "Træning",
+  "kcal": "{{count}} kcal",
+  "meter": "{{count}}m",
+  "kilometer": "{{count}}km",
+  "pace": "{{pace}}/100m",
+  "noPace": "--:--",
+  "stroke": {
+    "freestyle": "Fri crawl",
+    "backstroke": "Rygcrawl",
+    "breaststroke": "Brystsvømning",
+    "butterfly": "Butterfly",
+    "mixed": "Blandet"
+  },
+  "alert": {
+    "deleteWorkout": "Slet træning",
+    "deleteTemplate": "Slet skabelon",
+    "areYouSure": "Er du sikker?",
+    "deleteConfirm": "Slet \"{{name}}\"?"
+  }
+}
@@ -0,0 +1,10 @@
+{
+  "noCompletedYet": "Ingen fuldførte træninger endnu",
+  "lap": "Bane {{number}}",
+  "statistics": "Statistikker",
+  "thisWeek": "Denne uge",
+  "allTime": "Alt tid",
+  "personalBests": "Personlige rekorder",
+  "noDataYet": "Ingen data endnu",
+  "swolf": "SWOLF: {{value}}"
+}
@@ -0,0 +1,12 @@
+{
+  "workouts": "Træninger",
+  "history": "Historik",
+  "settings": "Indstillinger",
+  "newWorkout": "Ny træning",
+  "buildWorkout": "Opret træning",
+  "startSwim": "Start svømning",
+  "readyToSwim": "Klar til at svømme",
+  "swimComplete": "Svømning fuldført",
+  "session": "Session",
+  "sessionDetail": "Sessionsdetaljer"
+}
@@ -0,0 +1,7 @@
+{
+  "settings": "Indstillinger",
+  "defaultPoolLength": "Standard poolængde",
+  "language": "Sprog",
+  "systemLanguage": "Systemssprog",
+  "version": "SwimBuddy v1.0.0"
+}
@@ -0,0 +1,23 @@
+{
+  "workoutName": "Træningsnavn",
+  "poolLength": "Poolængde",
+  "stroke": "Svømmearm",
+  "distanceM": "Distance (m)",
+  "reps": "Gentagelser",
+  "restS": "Hvile (s)",
+  "addSet": "+ Tilføj sæt",
+  "remove": "Fjern",
+  "setNumber": "Sæt {{number}}",
+  "startSwim": "Start svømning",
+  "newWorkout": "+ Ny træning",
+  "noWorkoutsYet": "Ingen træninger endnu",
+  "tapNewWorkout": "Tryk på \"Ny træning\" for at komme i gang",
+  "morningSwim": "Morgensvømning",
+  "placeholder": {
+    "workoutName": "Morgensvømning"
+  },
+  "validation": {
+    "error": "Fejl",
+    "failedToSave": "Kunne ikke gemme træningen: {{error}}"
+  }
+}
@@ -0,0 +1,21 @@
+{
+  "workoutSentToWatch": "Workout sent to Watch!",
+  "openWatchApp": "Open the SwimBuddy app on your Apple Watch to start tracking.",
+  "failedToSend": "Failed to send",
+  "couldNotSend": "Could not send workout to Watch. Starting without Watch instead.",
+  "startWithoutWatch": "Start Without Watch",
+  "sendToWatchAndStart": "Send to Watch & Start",
+  "syncToWatch": "Workout will be synced to your Apple Watch",
+  "trackedOnDevice": "Workout will be tracked on this device",
+  "rest": "Rest",
+  "betweenSets": "{{duration}}s between sets",
+  "swimComplete": "Swim Complete!",
+  "greatJob": "Great job getting in the water today!",
+  "loadingSummary": "Loading summary...",
+  "watchStatus": {
+    "ready": "Apple Watch ready",
+    "pairedNotInRange": "Watch paired but not in range",
+    "pairedNotInstalled": "Watch paired, app not installed",
+    "noWatch": "No Watch paired"
+  }
+}
@@ -0,0 +1,43 @@
+{
+  "done": "Done",
+  "cancel": "Cancel",
+  "delete": "Delete",
+  "start": "Start",
+  "back": "Back",
+  "loading": "Loading...",
+  "error": "Error",
+  "save": "Save",
+  "saving": "Saving...",
+  "yes": "Yes",
+  "no": "No",
+  "confirm": "Confirm",
+  "ok": "OK",
+  "distance": "Distance",
+  "duration": "Duration",
+  "workouts": "Workouts",
+  "sets": "Sets",
+  "laps": "Laps",
+  "avgSwolf": "Avg SWOLF",
+  "pool": "{{length}}m pool",
+  "untitledWorkout": "Untitled Workout",
+  "swimSession": "Swim Session",
+  "workout": "Workout",
+  "kcal": "{{count}} kcal",
+  "meter": "{{count}}m",
+  "kilometer": "{{count}}km",
+  "pace": "{{pace}}/100m",
+  "noPace": "--:--",
+  "stroke": {
+    "freestyle": "Freestyle",
+    "backstroke": "Backstroke",
+    "breaststroke": "Breaststroke",
+    "butterfly": "Butterfly",
+    "mixed": "Mixed"
+  },
+  "alert": {
+    "deleteWorkout": "Delete Workout",
+    "deleteTemplate": "Delete Template",
+    "areYouSure": "Are you sure?",
+    "deleteConfirm": "Delete \"{{name}}\"?"
+  }
+}
@@ -0,0 +1,10 @@
+{
+  "noCompletedYet": "No completed workouts yet",
+  "lap": "Lap {{number}}",
+  "statistics": "Statistics",
+  "thisWeek": "This Week",
+  "allTime": "All Time",
+  "personalBests": "Personal Bests",
+  "noDataYet": "No data yet",
+  "swolf": "SWOLF: {{value}}"
+}
@@ -0,0 +1,12 @@
+{
+  "workouts": "Workouts",
+  "history": "History",
+  "settings": "Settings",
+  "newWorkout": "New Workout",
+  "buildWorkout": "Build Workout",
+  "startSwim": "Start Swim",
+  "readyToSwim": "Ready to Swim",
+  "swimComplete": "Swim Complete",
+  "session": "Session",
+  "sessionDetail": "Session Detail"
+}
@@ -0,0 +1,7 @@
+{
+  "settings": "Settings",
+  "defaultPoolLength": "Default Pool Length",
+  "language": "Language",
+  "systemLanguage": "System Language",
+  "version": "SwimBuddy v1.0.0"
+}
@@ -0,0 +1,23 @@
+{
+  "workoutName": "Workout Name",
+  "poolLength": "Pool Length",
+  "stroke": "Stroke",
+  "distanceM": "Distance (m)",
+  "reps": "Reps",
+  "restS": "Rest (s)",
+  "addSet": "+ Add Set",
+  "remove": "Remove",
+  "setNumber": "Set {{number}}",
+  "startSwim": "Start Swim",
+  "newWorkout": "+ New Workout",
+  "noWorkoutsYet": "No workouts yet",
+  "tapNewWorkout": "Tap \"New Workout\" to get started",
+  "morningSwim": "Morning Swim",
+  "placeholder": {
+    "workoutName": "Morning Swim"
+  },
+  "validation": {
+    "error": "Error",
+    "failedToSave": "Failed to save workout: {{error}}"
+  }
+}
@@ -0,0 +1,21 @@
+{
+  "workoutSentToWatch": "¡Entrenamiento enviado al Watch!",
+  "openWatchApp": "Abre la app SwimBuddy en tu Apple Watch para empezar el seguimiento.",
+  "failedToSend": "Error al enviar",
+  "couldNotSend": "No se pudo enviar el entrenamiento al Watch. Iniciando sin Watch.",
+  "startWithoutWatch": "Iniciar sin Watch",
+  "sendToWatchAndStart": "Enviar al Watch e iniciar",
+  "syncToWatch": "El entrenamiento se sincronizará con tu Apple Watch",
+  "trackedOnDevice": "El entrenamiento se rastreará en este dispositivo",
+  "rest": "Descanso",
+  "betweenSets": "{{duration}}s de descanso entre series",
+  "swimComplete": "¡Natación completada!",
+  "greatJob": "¡Buen trabajo! ¡Hoy has estado en el agua!",
+  "loadingSummary": "Cargando resumen...",
+  "watchStatus": {
+    "ready": "Apple Watch lista",
+    "pairedNotInRange": "Watch emparejada pero fuera de alcance",
+    "pairedNotInstalled": "Watch emparejada, app no instalada",
+    "noWatch": "Ninguna Watch emparejada"
+  }
+}
@@ -0,0 +1,43 @@
+{
+  "done": "Listo",
+  "cancel": "Cancelar",
+  "delete": "Eliminar",
+  "start": "Iniciar",
+  "back": "Volver",
+  "loading": "Cargando...",
+  "error": "Error",
+  "save": "Guardar",
+  "saving": "Guardando...",
+  "yes": "Sí",
+  "no": "No",
+  "confirm": "Confirmar",
+  "ok": "OK",
+  "distance": "Distancia",
+  "duration": "Duración",
+  "workouts": "Entrenamientos",
+  "sets": "Series",
+  "laps": "Largos",
+  "avgSwolf": "SWOLF prom.",
+  "pool": "Piscina de {{length}}m",
+  "untitledWorkout": "Entrenamiento sin nombre",
+  "swimSession": "Sesión de natación",
+  "workout": "Entrenamiento",
+  "kcal": "{{count}} kcal",
+  "meter": "{{count}}m",
+  "kilometer": "{{count}}km",
+  "pace": "{{pace}}/100m",
+  "noPace": "--:--",
+  "stroke": {
+    "freestyle": "Libre",
+    "backstroke": "Espalda",
+    "breaststroke": "Pecho",
+    "butterfly": "Mariposa",
+    "mixed": "Mixto"
+  },
+  "alert": {
+    "deleteWorkout": "Eliminar entrenamiento",
+    "deleteTemplate": "Eliminar plantilla",
+    "areYouSure": "¿Estás seguro?",
+    "deleteConfirm": "¿Eliminar \"{{name}}\"?"
+  }
+}
@@ -0,0 +1,10 @@
+{
+  "noCompletedYet": "Aún no hay entrenamientos completados",
+  "lap": "Largo {{number}}",
+  "statistics": "Estadísticas",
+  "thisWeek": "Esta semana",
+  "allTime": "Todos los tiempos",
+  "personalBests": "Récords personales",
+  "noDataYet": "Aún no hay datos",
+  "swolf": "SWOLF: {{value}}"
+}
@@ -0,0 +1,12 @@
+{
+  "workouts": "Entrenamientos",
+  "history": "Historial",
+  "settings": "Ajustes",
+  "newWorkout": "Nuevo entrenamiento",
+  "buildWorkout": "Crear entrenamiento",
+  "startSwim": "Iniciar natación",
+  "readyToSwim": "Listo para nadar",
+  "swimComplete": "Natación completada",
+  "session": "Sesión",
+  "sessionDetail": "Detalle de sesión"
+}
@@ -0,0 +1,7 @@
+{
+  "settings": "Ajustes",
+  "defaultPoolLength": "Longitud de piscina predeterminada",
+  "language": "Idioma",
+  "systemLanguage": "Idioma del sistema",
+  "version": "SwimBuddy v1.0.0"
+}
@@ -0,0 +1,23 @@
+{
+  "workoutName": "Nombre del entrenamiento",
+  "poolLength": "Longitud de la piscina",
+  "stroke": "Estilo",
+  "distanceM": "Distancia (m)",
+  "reps": "Repeticiones",
+  "restS": "Descanso (s)",
+  "addSet": "+ Añadir serie",
+  "remove": "Eliminar",
+  "setNumber": "Serie {{number}}",
+  "startSwim": "Iniciar natación",
+  "newWorkout": "+ Nuevo entrenamiento",
+  "noWorkoutsYet": "Aún no hay entrenamientos",
+  "tapNewWorkout": "Toca \"Nuevo entrenamiento\" para empezar",
+  "morningSwim": "Natación matutina",
+  "placeholder": {
+    "workoutName": "Natación matutina"
+  },
+  "validation": {
+    "error": "Error",
+    "failedToSave": "No se pudo guardar el entrenamiento: {{error}}"
+  }
+}
@@ -0,0 +1,21 @@
+{
+  "workoutSentToWatch": "Entraînement envoyé à la Watch !",
+  "openWatchApp": "Ouvrez l'application SwimBuddy sur votre Apple Watch pour commencer le suivi.",
+  "failedToSend": "Échec de l'envoi",
+  "couldNotSend": "Impossible d'envoyer l'entraînement à la Watch. Démarrage sans Watch.",
+  "startWithoutWatch": "Démarrer sans Watch",
+  "sendToWatchAndStart": "Envoyer à la Watch et commencer",
+  "syncToWatch": "L'entraînement sera synchronisé avec votre Apple Watch",
+  "trackedOnDevice": "L'entraînement sera suivi sur cet appareil",
+  "rest": "Repos",
+  "betweenSets": "{{duration}}s de repos entre les séries",
+  "swimComplete": "Nage terminée !",
+  "greatJob": "Bravo ! Vous êtes allé à l'eau aujourd'hui !",
+  "loadingSummary": "Chargement du résumé...",
+  "watchStatus": {
+    "ready": "Apple Watch prête",
+    "pairedNotInRange": "Watch appariée mais hors de portée",
+    "pairedNotInstalled": "Watch appariée, application non installée",
+    "noWatch": "Aucune Watch appariée"
+  }
+}
@@ -0,0 +1,43 @@
+{
+  "done": "Terminé",
+  "cancel": "Annuler",
+  "delete": "Supprimer",
+  "start": "Commencer",
+  "back": "Retour",
+  "loading": "Chargement...",
+  "error": "Erreur",
+  "save": "Enregistrer",
+  "saving": "Enregistrement...",
+  "yes": "Oui",
+  "no": "Non",
+  "confirm": "Confirmer",
+  "ok": "OK",
+  "distance": "Distance",
+  "duration": "Durée",
+  "workouts": "Entraînements",
+  "sets": "Séries",
+  "laps": "Longueurs",
+  "avgSwolf": "SWOLF moy.",
+  "pool": "Bassin de {{length}}m",
+  "untitledWorkout": "Entraînement sans titre",
+  "swimSession": "Séance de natation",
+  "workout": "Entraînement",
+  "kcal": "{{count}} kcal",
+  "meter": "{{count}}m",
+  "kilometer": "{{count}}km",
+  "pace": "{{pace}}/100m",
+  "noPace": "--:--",
+  "stroke": {
+    "freestyle": "Nage libre",
+    "backstroke": "Dos",
+    "breaststroke": "Brasse",
+    "butterfly": "Papillon",
+    "mixed": "Mixte"
+  },
+  "alert": {
+    "deleteWorkout": "Supprimer l'entraînement",
+    "deleteTemplate": "Supprimer le modèle",
+    "areYouSure": "Êtes-vous sûr ?",
+    "deleteConfirm": "Supprimer \"{{name}}\" ?"
+  }
+}
@@ -0,0 +1,10 @@
+{
+  "noCompletedYet": "Aucun entraînement terminé pour le moment",
+  "lap": "Longueur {{number}}",
+  "statistics": "Statistiques",
+  "thisWeek": "Cette semaine",
+  "allTime": "Tout le temps",
+  "personalBests": "Records personnels",
+  "noDataYet": "Pas encore de données",
+  "swolf": "SWOLF : {{value}}"
+}
@@ -0,0 +1,12 @@
+{
+  "workouts": "Entraînements",
+  "history": "Historique",
+  "settings": "Paramètres",
+  "newWorkout": "Nouvel entraînement",
+  "buildWorkout": "Créer un entraînement",
+  "startSwim": "Commencer la nage",
+  "readyToSwim": "Prêt à nager",
+  "swimComplete": "Nage terminée",
+  "session": "Séance",
+  "sessionDetail": "Détails de la séance"
+}
@@ -0,0 +1,7 @@
+{
+  "settings": "Paramètres",
+  "defaultPoolLength": "Longueur du bassin par défaut",
+  "language": "Langue",
+  "systemLanguage": "Langue du système",
+  "version": "SwimBuddy v1.0.0"
+}
@@ -0,0 +1,23 @@
+{
+  "workoutName": "Nom de l'entraînement",
+  "poolLength": "Longueur du bassin",
+  "stroke": "Style",
+  "distanceM": "Distance (m)",
+  "reps": "Répétitions",
+  "restS": "Repos (s)",
+  "addSet": "+ Ajouter une série",
+  "remove": "Retirer",
+  "setNumber": "Série {{number}}",
+  "startSwim": "Commencer la nage",
+  "newWorkout": "+ Nouvel entraînement",
+  "noWorkoutsYet": "Aucun entraînement pour le moment",
+  "tapNewWorkout": "Appuyez sur \"Nouvel entraînement\" pour commencer",
+  "morningSwim": "Matinée de natation",
+  "placeholder": {
+    "workoutName": "Matinée de natation"
+  },
+  "validation": {
+    "error": "Erreur",
+    "failedToSave": "Échec de l'enregistrement : {{error}}"
+  }
+}
@@ -0,0 +1,231 @@
+import { useRef, useEffect } from "react";
+import { AppState, type AppStateStatus } from "react-native";
+import i18n from "i18next";
+import { initReactI18next } from "react-i18next";
+import { getLocales } from "expo-localization";
+import { createMMKV } from "react-native-mmkv";
+
+import enCommon from "./en/common.json";
+import enNavigation from "./en/navigation.json";
+import enWorkout from "./en/workout.json";
+import enActiveWorkout from "./en/active-workout.json";
+import enHistory from "./en/history.json";
+import enSettings from "./en/settings.json";
+
+import nlCommon from "./nl/common.json";
+import nlNavigation from "./nl/navigation.json";
+import nlWorkout from "./nl/workout.json";
+import nlActiveWorkout from "./nl/active-workout.json";
+import nlHistory from "./nl/history.json";
+import nlSettings from "./nl/settings.json";
+
+import deCommon from "./de/common.json";
+import deNavigation from "./de/navigation.json";
+import deWorkout from "./de/workout.json";
+import deActiveWorkout from "./de/active-workout.json";
+import deHistory from "./de/history.json";
+import deSettings from "./de/settings.json";
+
+import frCommon from "./fr/common.json";
+import frNavigation from "./fr/navigation.json";
+import frWorkout from "./fr/workout.json";
+import frActiveWorkout from "./fr/active-workout.json";
+import frHistory from "./fr/history.json";
+import frSettings from "./fr/settings.json";
+
+import itCommon from "./it/common.json";
+import itNavigation from "./it/navigation.json";
+import itWorkout from "./it/workout.json";
+import itActiveWorkout from "./it/active-workout.json";
+import itHistory from "./it/history.json";
+import itSettings from "./it/settings.json";
+
+import esCommon from "./es/common.json";
+import esNavigation from "./es/navigation.json";
+import esWorkout from "./es/workout.json";
+import esActiveWorkout from "./es/active-workout.json";
+import esHistory from "./es/history.json";
+import esSettings from "./es/settings.json";
+
+import plCommon from "./pl/common.json";
+import plNavigation from "./pl/navigation.json";
+import plWorkout from "./pl/workout.json";
+import plActiveWorkout from "./pl/active-workout.json";
+import plHistory from "./pl/history.json";
+import plSettings from "./pl/settings.json";
+
+import ptCommon from "./pt/common.json";
+import ptNavigation from "./pt/navigation.json";
+import ptWorkout from "./pt/workout.json";
+import ptActiveWorkout from "./pt/active-workout.json";
+import ptHistory from "./pt/history.json";
+import ptSettings from "./pt/settings.json";
+
+import dkCommon from "./dk/common.json";
+import dkNavigation from "./dk/navigation.json";
+import dkWorkout from "./dk/workout.json";
+import dkActiveWorkout from "./dk/active-workout.json";
+import dkHistory from "./dk/history.json";
+import dkSettings from "./dk/settings.json";
+
+export const LANGUAGES = [
+  { code: "en", label: "English" },
+  { code: "nl", label: "Nederlands" },
+  { code: "de", label: "Deutsch" },
+  { code: "fr", label: "Français" },
+  { code: "it", label: "Italiano" },
+  { code: "es", label: "Español" },
+  { code: "pl", label: "Polski" },
+  { code: "pt", label: "Português" },
+  { code: "dk", label: "Dansk" },
+] as const;
+
+export type LanguageCode = (typeof LANGUAGES)[number]["code"];
+
+export type StoredLanguage = LanguageCode | "system";
+
+const namespaces = [
+  "common",
+  "navigation",
+  "workout",
+  "active-workout",
+  "history",
+  "settings",
+] as const;
+
+export type Namespace = (typeof namespaces)[number];
+
+const storage = createMMKV({ id: "i18n-settings" });
+
+export function getStoredLanguage(): StoredLanguage | undefined {
+  const stored = storage.getString("language");
+  if (stored === "system") return "system";
+  if (stored && LANGUAGES.some((l) => l.code === stored)) {
+    return stored as LanguageCode;
+  }
+  return undefined;
+}
+
+export function setStoredLanguage(code: StoredLanguage) {
+  storage.set("language", code);
+}
+
+export function getDeviceLanguage(): LanguageCode {
+  const deviceLocale = getLocales()[0]?.languageCode ?? "en";
+  if (LANGUAGES.some((l) => l.code === deviceLocale)) {
+    return deviceLocale as LanguageCode;
+  }
+  return "en";
+}
+
+export function resolveLanguage(stored: StoredLanguage | undefined): LanguageCode {
+  if (stored === "system" || stored === undefined) return getDeviceLanguage();
+  return stored;
+}
+
+export function useSystemLanguageListener() {
+  const appState = useRef(AppState.currentState);
+
+  useEffect(() => {
+    const subscription = AppState.addEventListener("change", (nextState: AppStateStatus) => {
+      if (appState.current.match(/inactive|background/) && nextState === "active") {
+        const stored = getStoredLanguage();
+        if (stored === "system") {
+          const deviceLang = getDeviceLanguage();
+          if (i18n.language !== deviceLang) {
+            i18n.changeLanguage(deviceLang);
+          }
+        }
+      }
+      appState.current = nextState;
+    });
+
+    return () => subscription.remove();
+  }, []);
+}
+
+i18n.use(initReactI18next).init({
+  resources: {
+    en: {
+      common: enCommon,
+      navigation: enNavigation,
+      workout: enWorkout,
+      "active-workout": enActiveWorkout,
+      history: enHistory,
+      settings: enSettings,
+    },
+    nl: {
+      common: nlCommon,
+      navigation: nlNavigation,
+      workout: nlWorkout,
+      "active-workout": nlActiveWorkout,
+      history: nlHistory,
+      settings: nlSettings,
+    },
+    de: {
+      common: deCommon,
+      navigation: deNavigation,
+      workout: deWorkout,
+      "active-workout": deActiveWorkout,
+      history: deHistory,
+      settings: deSettings,
+    },
+    fr: {
+      common: frCommon,
+      navigation: frNavigation,
+      workout: frWorkout,
+      "active-workout": frActiveWorkout,
+      history: frHistory,
+      settings: frSettings,
+    },
+    it: {
+      common: itCommon,
+      navigation: itNavigation,
+      workout: itWorkout,
+      "active-workout": itActiveWorkout,
+      history: itHistory,
+      settings: itSettings,
+    },
+    es: {
+      common: esCommon,
+      navigation: esNavigation,
+      workout: esWorkout,
+      "active-workout": esActiveWorkout,
+      history: esHistory,
+      settings: esSettings,
+    },
+    pl: {
+      common: plCommon,
+      navigation: plNavigation,
+      workout: plWorkout,
+      "active-workout": plActiveWorkout,
+      history: plHistory,
+      settings: plSettings,
+    },
+    pt: {
+      common: ptCommon,
+      navigation: ptNavigation,
+      workout: ptWorkout,
+      "active-workout": ptActiveWorkout,
+      history: ptHistory,
+      settings: ptSettings,
+    },
+    dk: {
+      common: dkCommon,
+      navigation: dkNavigation,
+      workout: dkWorkout,
+      "active-workout": dkActiveWorkout,
+      history: dkHistory,
+      settings: dkSettings,
+    },
+  },
+  lng: resolveLanguage(getStoredLanguage()),
+  fallbackLng: "en",
+  ns: [...namespaces],
+  defaultNS: "common",
+  interpolation: {
+    escapeValue: false,
+  },
+});
+
+export default i18n;
@@ -0,0 +1,21 @@
+{
+  "workoutSentToWatch": "Allenamento inviato alla Watch!",
+  "openWatchApp": "Apri l'app SwimBuddy sulla tua Apple Watch per iniziare il monitoraggio.",
+  "failedToSend": "Invio fallito",
+  "couldNotSend": "Impossibile inviare l'allenamento alla Watch. Avvio senza Watch.",
+  "startWithoutWatch": "Avvia senza Watch",
+  "sendToWatchAndStart": "Invia alla Watch e avvia",
+  "syncToWatch": "L'allenamento verrà sincronizzato con la tua Apple Watch",
+  "trackedOnDevice": "L'allenamento verrà monitorato su questo dispositivo",
+  "rest": "Recupero",
+  "betweenSets": "{{duration}}s di recupero tra le serie",
+  "swimComplete": "Nuoto completato!",
+  "greatJob": "Ottimo lavoro! Sei entrato in acqua oggi!",
+  "loadingSummary": "Caricamento riepilogo...",
+  "watchStatus": {
+    "ready": "Apple Watch pronta",
+    "pairedNotInRange": "Watch associata ma fuori portata",
+    "pairedNotInstalled": "Watch associata, app non installata",
+    "noWatch": "Nessuna Watch associata"
+  }
+}
@@ -0,0 +1,43 @@
+{
+  "done": "Fatto",
+  "cancel": "Annulla",
+  "delete": "Elimina",
+  "start": "Inizia",
+  "back": "Indietro",
+  "loading": "Caricamento...",
+  "error": "Errore",
+  "save": "Salva",
+  "saving": "Salvataggio...",
+  "yes": "Sì",
+  "no": "No",
+  "confirm": "Conferma",
+  "ok": "OK",
+  "distance": "Distanza",
+  "duration": "Durata",
+  "workouts": "Allenamenti",
+  "sets": "Serie",
+  "laps": "Lunghezze",
+  "avgSwolf": "SWOLF media",
+  "pool": "Piscina di {{length}}m",
+  "untitledWorkout": "Allenamento senza nome",
+  "swimSession": "Sessione di nuoto",
+  "workout": "Allenamento",
+  "kcal": "{{count}} kcal",
+  "meter": "{{count}}m",
+  "kilometer": "{{count}}km",
+  "pace": "{{pace}}/100m",
+  "noPace": "--:--",
+  "stroke": {
+    "freestyle": "Stile libero",
+    "backstroke": "Dorso",
+    "breaststroke": "Rana",
+    "butterfly": "Farfalla",
+    "mixed": "Misto"
+  },
+  "alert": {
+    "deleteWorkout": "Elimina allenamento",
+    "deleteTemplate": "Elimina modello",
+    "areYouSure": "Sei sicuro?",
+    "deleteConfirm": "Eliminare \"{{name}}\"?"
+  }
+}
@@ -0,0 +1,10 @@
+{
+  "noCompletedYet": "Nessun allenamento completato ancora",
+  "lap": "Lunghezza {{number}}",
+  "statistics": "Statistiche",
+  "thisWeek": "Questa settimana",
+  "allTime": "Tutti i tempi",
+  "personalBests": "Record personali",
+  "noDataYet": "Nessun dato ancora",
+  "swolf": "SWOLF: {{value}}"
+}
@@ -0,0 +1,12 @@
+{
+  "workouts": "Allenamenti",
+  "history": "Cronologia",
+  "settings": "Impostazioni",
+  "newWorkout": "Nuovo allenamento",
+  "buildWorkout": "Crea allenamento",
+  "startSwim": "Inizia nuoto",
+  "readyToSwim": "Pronto per nuotare",
+  "swimComplete": "Nuoto completato",
+  "session": "Sessione",
+  "sessionDetail": "Dettagli sessione"
+}
@@ -0,0 +1,7 @@
+{
+  "settings": "Impostazioni",
+  "defaultPoolLength": "Lunghezza piscina predefinita",
+  "language": "Lingua",
+  "systemLanguage": "Lingua di sistema",
+  "version": "SwimBuddy v1.0.0"
+}
@@ -0,0 +1,23 @@
+{
+  "workoutName": "Nome allenamento",
+  "poolLength": "Lunghezza piscina",
+  "stroke": "Stile",
+  "distanceM": "Distanza (m)",
+  "reps": "Ripetizioni",
+  "restS": "Recupero (s)",
+  "addSet": "+ Aggiungi serie",
+  "remove": "Rimuovi",
+  "setNumber": "Serie {{number}}",
+  "startSwim": "Inizia nuoto",
+  "newWorkout": "+ Nuovo allenamento",
+  "noWorkoutsYet": "Nessun allenamento ancora",
+  "tapNewWorkout": "Tocca \"Nuovo allenamento\" per iniziare",
+  "morningSwim": "Nuoto mattutino",
+  "placeholder": {
+    "workoutName": "Nuoto mattutino"
+  },
+  "validation": {
+    "error": "Errore",
+    "failedToSave": "Impossibile salvare l'allenamento: {{error}}"
+  }
+}
@@ -0,0 +1,21 @@
+{
+  "workoutSentToWatch": "Workout verzonden naar Watch!",
+  "openWatchApp": "Open de SwimBuddy-app op je Apple Watch om te beginnen met bijhouden.",
+  "failedToSend": "Verzenden mislukt",
+  "couldNotSend": "Kon workout niet naar Watch verzenden. Start zonder Watch.",
+  "startWithoutWatch": "Start zonder Watch",
+  "sendToWatchAndStart": "Verzenden naar Watch & Start",
+  "syncToWatch": "Workout wordt gesynchroniseerd naar je Apple Watch",
+  "trackedOnDevice": "Workout wordt op dit apparaat bijgehouden",
+  "rest": "Rust",
+  "betweenSets": "{{duration}}s rust tussen sets",
+  "swimComplete": "Zwemmen voltooid!",
+  "greatJob": "Goed gedaan! Je bent vandaag het water in geweest!",
+  "loadingSummary": "Samenvatting laden...",
+  "watchStatus": {
+    "ready": "Apple Watch gereed",
+    "pairedNotInRange": "Watch gekoppeld maar niet in bereik",
+    "pairedNotInstalled": "Watch gekoppeld, app niet geïnstalleerd",
+    "noWatch": "Geen Watch gekoppeld"
+  }
+}
@@ -0,0 +1,43 @@
+{
+  "done": "Gereed",
+  "cancel": "Annuleren",
+  "delete": "Verwijderen",
+  "start": "Start",
+  "back": "Terug",
+  "loading": "Laden...",
+  "error": "Fout",
+  "save": "Opslaan",
+  "saving": "Opslaan...",
+  "yes": "Ja",
+  "no": "Nee",
+  "confirm": "Bevestigen",
+  "ok": "OK",
+  "distance": "Afstand",
+  "duration": "Duur",
+  "workouts": "Workouts",
+  "sets": "Sets",
+  "laps": "Banen",
+  "avgSwolf": "Gem. SWOLF",
+  "pool": "{{length}}m bad",
+  "untitledWorkout": "Naamloze Workout",
+  "swimSession": "Zwemsessie",
+  "workout": "Workout",
+  "kcal": "{{count}} kcal",
+  "meter": "{{count}}m",
+  "kilometer": "{{count}}km",
+  "pace": "{{pace}}/100m",
+  "noPace": "--:--",
+  "stroke": {
+    "freestyle": "Vrije slag",
+    "backstroke": "Rugslag",
+    "breaststroke": "Schoolslag",
+    "butterfly": "Vlinderslag",
+    "mixed": "Gemengd"
+  },
+  "alert": {
+    "deleteWorkout": "Workout verwijderen",
+    "deleteTemplate": "Sjabloon verwijderen",
+    "areYouSure": "Weet je het zeker?",
+    "deleteConfirm": "\"{{name}}\" verwijderen?"
+  }
+}
@@ -0,0 +1,10 @@
+{
+  "noCompletedYet": "Nog geen voltooide workouts",
+  "lap": "Baan {{number}}",
+  "statistics": "Statistieken",
+  "thisWeek": "Deze week",
+  "allTime": "Alle tijd",
+  "personalBests": "Persoonlijke records",
+  "noDataYet": "Nog geen gegevens",
+  "swolf": "SWOLF: {{value}}"
+}
@@ -0,0 +1,12 @@
+{
+  "workouts": "Workouts",
+  "history": "Geschiedenis",
+  "settings": "Instellingen",
+  "newWorkout": "Nieuwe Workout",
+  "buildWorkout": "Workout samenstellen",
+  "startSwim": "Start Zwemmen",
+  "readyToSwim": "Klaar om te zwemmen",
+  "swimComplete": "Zwemmen voltooid",
+  "session": "Sessie",
+  "sessionDetail": "Sessiedetails"
+}
@@ -0,0 +1,7 @@
+{
+  "settings": "Instellingen",
+  "defaultPoolLength": "Standaard badlengte",
+  "language": "Taal",
+  "systemLanguage": "Systeemtaal",
+  "version": "SwimBuddy v1.0.0"
+}
@@ -0,0 +1,23 @@
+{
+  "workoutName": "Workoutnaam",
+  "poolLength": "Badlengte",
+  "stroke": "Slag",
+  "distanceM": "Afstand (m)",
+  "reps": "Herhalingen",
+  "restS": "Rust (s)",
+  "addSet": "+ Set toevoegen",
+  "remove": "Verwijderen",
+  "setNumber": "Set {{number}}",
+  "startSwim": "Start Zwemmen",
+  "newWorkout": "+ Nieuwe Workout",
+  "noWorkoutsYet": "Nog geen workouts",
+  "tapNewWorkout": "Tik op \"Nieuwe Workout\" om te beginnen",
+  "morningSwim": "Ochtendzwemmen",
+  "placeholder": {
+    "workoutName": "Ochtendzwemmen"
+  },
+  "validation": {
+    "error": "Fout",
+    "failedToSave": "Workout opslaan mislukt: {{error}}"
+  }
+}
@@ -0,0 +1,21 @@
+{
+  "workoutSentToWatch": "Trening wysłany do Watch!",
+  "openWatchApp": "Otwórz aplikację SwimBuddy na swojej Apple Watch, aby rozpocząć śledzenie.",
+  "failedToSend": "Nie udało się wysłać",
+  "couldNotSend": "Nie udało się wysłać treningu do Watch. Uruchamianie bez Watch.",
+  "startWithoutWatch": "Uruchom bez Watch",
+  "sendToWatchAndStart": "Wyślij do Watch i rozpocznij",
+  "syncToWatch": "Trening zostanie zsynchronizowany z Apple Watch",
+  "trackedOnDevice": "Trening będzie śledzony na tym urządzeniu",
+  "rest": "Odpoczynek",
+  "betweenSets": "{{duration}}s odpoczynku między seriami",
+  "swimComplete": "Pływanie zakończone!",
+  "greatJob": "Świetna robota! Dziś byłeś w wodzie!",
+  "loadingSummary": "Ładowanie podsumowania...",
+  "watchStatus": {
+    "ready": "Apple Watch gotowa",
+    "pairedNotInRange": "Watch sparowana, ale poza zasięgiem",
+    "pairedNotInstalled": "Watch sparowana, aplikacja nie zainstalowana",
+    "noWatch": "Brak sparowanej Watch"
+  }
+}
@@ -0,0 +1,43 @@
+{
+  "done": "Gotowe",
+  "cancel": "Anuluj",
+  "delete": "Usuń",
+  "start": "Rozpocznij",
+  "back": "Wstecz",
+  "loading": "Ładowanie...",
+  "error": "Błąd",
+  "save": "Zapisz",
+  "saving": "Zapisywanie...",
+  "yes": "Tak",
+  "no": "Nie",
+  "confirm": "Potwierdź",
+  "ok": "OK",
+  "distance": "Dystans",
+  "duration": "Czas",
+  "workouts": "Treningi",
+  "sets": "Serie",
+  "laps": "Długości",
+  "avgSwolf": "Śr. SWOLF",
+  "pool": "Basen {{length}}m",
+  "untitledWorkout": "Trening bez nazwy",
+  "swimSession": "Sesja pływacka",
+  "workout": "Trening",
+  "kcal": "{{count}} kcal",
+  "meter": "{{count}}m",
+  "kilometer": "{{count}}km",
+  "pace": "{{pace}}/100m",
+  "noPace": "--:--",
+  "stroke": {
+    "freestyle": "Styl dowolny",
+    "backstroke": "Grzbietowy",
+    "breaststroke": "Klasyk",
+    "butterfly": "Delfin",
+    "mixed": "Mieszany"
+  },
+  "alert": {
+    "deleteWorkout": "Usuń trening",
+    "deleteTemplate": "Usuń szablon",
+    "areYouSure": "Na pewno?",
+    "deleteConfirm": "Usunąć \"{{name}}\"?"
+  }
+}
@@ -0,0 +1,10 @@
+{
+  "noCompletedYet": "Brak ukończonych treningów",
+  "lap": "Długość {{number}}",
+  "statistics": "Statystyki",
+  "thisWeek": "Ten tydzień",
+  "allTime": "Cały okres",
+  "personalBests": "Rekordy osobiste",
+  "noDataYet": "Brak danych",
+  "swolf": "SWOLF: {{value}}"
+}
@@ -0,0 +1,12 @@
+{
+  "workouts": "Treningi",
+  "history": "Historia",
+  "settings": "Ustawienia",
+  "newWorkout": "Nowy trening",
+  "buildWorkout": "Stwórz trening",
+  "startSwim": "Rozpocznij pływanie",
+  "readyToSwim": "Gotowy do pływania",
+  "swimComplete": "Pływanie zakończone",
+  "session": "Sesja",
+  "sessionDetail": "Szczegóły sesji"
+}
@@ -0,0 +1,7 @@
+{
+  "settings": "Ustawienia",
+  "defaultPoolLength": "Domyślna długość basenu",
+  "language": "Język",
+  "systemLanguage": "Język systemowy",
+  "version": "SwimBuddy v1.0.0"
+}
@@ -0,0 +1,23 @@
+{
+  "workoutName": "Nazwa treningu",
+  "poolLength": "Długość basenu",
+  "stroke": "Styl",
+  "distanceM": "Dystans (m)",
+  "reps": "Powtórzenia",
+  "restS": "Odpoczynek (s)",
+  "addSet": "+ Dodaj serię",
+  "remove": "Usuń",
+  "setNumber": "Seria {{number}}",
+  "startSwim": "Rozpocznij pływanie",
+  "newWorkout": "+ Nowy trening",
+  "noWorkoutsYet": "Brak treningów",
+  "tapNewWorkout": "Stuknij \"Nowy trening\" aby rozpocząć",
+  "morningSwim": "Poranne pływanie",
+  "placeholder": {
+    "workoutName": "Poranne pływanie"
+  },
+  "validation": {
+    "error": "Błąd",
+    "failedToSave": "Nie udało się zapisać treningu: {{error}}"
+  }
+}
@@ -0,0 +1,21 @@
+{
+  "workoutSentToWatch": "Treino enviado para a Watch!",
+  "openWatchApp": "Abra a aplicação SwimBuddy na sua Apple Watch para iniciar o registo.",
+  "failedToSend": "Falha no envio",
+  "couldNotSend": "Não foi possível enviar o treino para a Watch. Iniciando sem Watch.",
+  "startWithoutWatch": "Iniciar sem Watch",
+  "sendToWatchAndStart": "Enviar para a Watch e iniciar",
+  "syncToWatch": "O treino será sincronizado com a sua Apple Watch",
+  "trackedOnDevice": "O treino será registado neste dispositivo",
+  "rest": "Descanso",
+  "betweenSets": "{{duration}}s de descanso entre séries",
+  "swimComplete": "Natação concluída!",
+  "greatJob": "Bom trabalho! Esteve na água hoje!",
+  "loadingSummary": "A carregar resumo...",
+  "watchStatus": {
+    "ready": "Apple Watch pronta",
+    "pairedNotInRange": "Watch associada, mas fora de alcance",
+    "pairedNotInstalled": "Watch associada, aplicação não instalada",
+    "noWatch": "Nenhuma Watch associada"
+  }
+}
@@ -0,0 +1,43 @@
+{
+  "done": "Concluído",
+  "cancel": "Cancelar",
+  "delete": "Eliminar",
+  "start": "Iniciar",
+  "back": "Voltar",
+  "loading": "A carregar...",
+  "error": "Erro",
+  "save": "Guardar",
+  "saving": "A guardar...",
+  "yes": "Sim",
+  "no": "Não",
+  "confirm": "Confirmar",
+  "ok": "OK",
+  "distance": "Distância",
+  "duration": "Duração",
+  "workouts": "Treinos",
+  "sets": "Séries",
+  "laps": "Comprimentos",
+  "avgSwolf": "SWOLF médio",
+  "pool": "Piscina de {{length}}m",
+  "untitledWorkout": "Treino sem nome",
+  "swimSession": "Sessão de natação",
+  "workout": "Treino",
+  "kcal": "{{count}} kcal",
+  "meter": "{{count}}m",
+  "kilometer": "{{count}}km",
+  "pace": "{{pace}}/100m",
+  "noPace": "--:--",
+  "stroke": {
+    "freestyle": "Estilo livre",
+    "backstroke": "Costas",
+    "breaststroke": "Peito",
+    "butterfly": "Borboleta",
+    "mixed": "Misto"
+  },
+  "alert": {
+    "deleteWorkout": "Eliminar treino",
+    "deleteTemplate": "Eliminar modelo",
+    "areYouSure": "Tem certeza?",
+    "deleteConfirm": "Eliminar \"{{name}}\"?"
+  }
+}
@@ -0,0 +1,10 @@
+{
+  "noCompletedYet": "Ainda não há treinos concluídos",
+  "lap": "Comprimento {{number}}",
+  "statistics": "Estatísticas",
+  "thisWeek": "Esta semana",
+  "allTime": "Todo o tempo",
+  "personalBests": "Recordes pessoais",
+  "noDataYet": "Ainda sem dados",
+  "swolf": "SWOLF: {{value}}"
+}
@@ -0,0 +1,12 @@
+{
+  "workouts": "Treinos",
+  "history": "Histórico",
+  "settings": "Definições",
+  "newWorkout": "Novo treino",
+  "buildWorkout": "Criar treino",
+  "startSwim": "Iniciar natação",
+  "readyToSwim": "Pronto para nadar",
+  "swimComplete": "Natação concluída",
+  "session": "Sessão",
+  "sessionDetail": "Detalhes da sessão"
+}
@@ -0,0 +1,7 @@
+{
+  "settings": "Definições",
+  "defaultPoolLength": "Comprimento de piscina predefinido",
+  "language": "Idioma",
+  "systemLanguage": "Idioma do sistema",
+  "version": "SwimBuddy v1.0.0"
+}
@@ -0,0 +1,23 @@
+{
+  "workoutName": "Nome do treino",
+  "poolLength": "Comprimento da piscina",
+  "stroke": "Estilo",
+  "distanceM": "Distância (m)",
+  "reps": "Repetições",
+  "restS": "Descanso (s)",
+  "addSet": "+ Adicionar série",
+  "remove": "Remover",
+  "setNumber": "Série {{number}}",
+  "startSwim": "Iniciar natação",
+  "newWorkout": "+ Novo treino",
+  "noWorkoutsYet": "Ainda não há treinos",
+  "tapNewWorkout": "Toque em \"Novo treino\" para começar",
+  "morningSwim": "Natação matinal",
+  "placeholder": {
+    "workoutName": "Natação matinal"
+  },
+  "validation": {
+    "error": "Erro",
+    "failedToSave": "Falha ao guardar o treino: {{error}}"
+  }
+}
@@ -1,3 +1,4 @@
+import { useTranslation } from "react-i18next";
 import { createNativeStackNavigator } from "@react-navigation/native-stack";
 import { HistoryStackParamList } from "./types";
 import { HistoryScreen } from "../features/history/screens/HistoryScreen";
@@ -6,6 +7,8 @@ import { SessionDetailScreen } from "../features/history/screens/SessionDetailSc
 const Stack = createNativeStackNavigator<HistoryStackParamList>();

 export function HistoryNavigator() {
+  const { t } = useTranslation("navigation");
+
  return (
    <Stack.Navigator
      screenOptions={{
@@ -17,12 +20,12 @@ export function HistoryNavigator() {
      <Stack.Screen
        name="HistoryList"
        component={HistoryScreen}
-        options={{ title: "History" }}
+        options={{ title: t("history") }}
      />
      <Stack.Screen
        name="SessionDetail"
        component={SessionDetailScreen}
-        options={{ title: "Session Detail" }}
+        options={{ title: t("sessionDetail") }}
      />
    </Stack.Navigator>
  );
@@ -1,3 +1,4 @@
+import { useTranslation } from "react-i18next";
 import { createBottomTabNavigator } from "@react-navigation/bottom-tabs";
 import { Ionicons } from "@expo/vector-icons";
 import { MainTabParamList } from "./types";
@@ -8,6 +9,8 @@ import { SettingsScreen } from "../features/settings/screens/SettingsScreen";
 const Tab = createBottomTabNavigator<MainTabParamList>();

 export function MainTabNavigator() {
+  const { t } = useTranslation("navigation");
+
  return (
    <Tab.Navigator
      screenOptions={{
@@ -23,6 +26,7 @@ export function MainTabNavigator() {
        component={WorkoutNavigator}
        options={{
          headerShown: false,
+          tabBarLabel: t("workouts"),
          tabBarIcon: ({ color, size }) => (
            <Ionicons name="water" size={size} color={color} />
          ),
@@ -33,6 +37,7 @@ export function MainTabNavigator() {
        component={HistoryNavigator}
        options={{
          headerShown: false,
+          tabBarLabel: t("history"),
          tabBarIcon: ({ color, size }) => (
            <Ionicons name="time-outline" size={size} color={color} />
          ),
@@ -42,6 +47,7 @@ export function MainTabNavigator() {
        name="Settings"
        component={SettingsScreen}
        options={{
+          tabBarLabel: t("settings"),
          tabBarIcon: ({ color, size }) => (
            <Ionicons name="settings-outline" size={size} color={color} />
          ),
@@ -1,3 +1,4 @@
+import { useTranslation } from "react-i18next";
 import { createNativeStackNavigator } from "@react-navigation/native-stack";
 import { MainTabNavigator } from "./MainTabNavigator";
 import { RootStackParamList } from "./types";
@@ -9,6 +10,8 @@ import { SessionDetailScreen } from "../features/history/screens/SessionDetailSc
 const Stack = createNativeStackNavigator<RootStackParamList>();

 export function RootNavigator() {
+  const { t } = useTranslation("navigation");
+
  return (
    <Stack.Navigator
      screenOptions={{
@@ -25,22 +28,22 @@ export function RootNavigator() {
      <Stack.Screen
        name="WorkoutBuilder"
        component={BuilderScreen}
-        options={{ title: "New Workout" }}
+        options={{ title: t("newWorkout") }}
      />
      <Stack.Screen
        name="PreSwim"
        component={PreSwimScreen}
-        options={{ title: "Ready to Swim" }}
+        options={{ title: t("readyToSwim") }}
      />
      <Stack.Screen
        name="PostSwim"
        component={PostSwimScreen}
-        options={{ title: "Swim Complete", headerLeft: () => null }}
+        options={{ title: t("swimComplete"), headerLeft: () => null }}
      />
      <Stack.Screen
        name="SessionDetail"
        component={SessionDetailScreen}
-        options={{ title: "Session" }}
+        options={{ title: t("session") }}
      />
    </Stack.Navigator>
  );
@@ -1,3 +1,4 @@
+import { useTranslation } from "react-i18next";
 import { createNativeStackNavigator } from "@react-navigation/native-stack";
 import { WorkoutStackParamList } from "./types";
 import { WorkoutListScreen } from "../features/workout-builder/screens/WorkoutListScreen";
@@ -7,6 +8,8 @@ import { PreSwimScreen } from "../features/active-workout/screens/PreSwimScreen"
 const Stack = createNativeStackNavigator<WorkoutStackParamList>();

 export function WorkoutNavigator() {
+  const { t } = useTranslation("navigation");
+
  return (
    <Stack.Navigator
      screenOptions={{
@@ -18,17 +21,17 @@ export function WorkoutNavigator() {
      <Stack.Screen
        name="WorkoutList"
        component={WorkoutListScreen}
-        options={{ title: "Workouts" }}
+        options={{ title: t("workouts") }}
      />
      <Stack.Screen
        name="Builder"
        component={BuilderScreen}
-        options={{ title: "Build Workout" }}
+        options={{ title: t("buildWorkout") }}
      />
      <Stack.Screen
        name="PreSwim"
        component={PreSwimScreen}
-        options={{ title: "Start Swim" }}
+        options={{ title: t("startSwim") }}
      />
    </Stack.Navigator>
  );
@@ -1,16 +1,27 @@
-import { createContext, useContext, useEffect, useState, type ReactNode } from "react";
+import { createContext, useContext, useState, type ReactNode } from "react";
 import { createMMKV } from "react-native-mmkv";
+import i18n, {
+  type LanguageCode,
+  type StoredLanguage,
+  getStoredLanguage,
+  setStoredLanguage,
+  resolveLanguage,
+} from "../i18n";

 const storage = createMMKV();

 type SettingsContextType = {
  poolLength: number;
  setPoolLength: (length: number) => void;
+  language: StoredLanguage;
+  setLanguage: (code: StoredLanguage) => void;
 };

 const SettingsContext = createContext<SettingsContextType>({
  poolLength: 25,
  setPoolLength: () => {},
+  language: "system",
+  setLanguage: () => {},
 });

 export function useSettings() {
@@ -23,13 +34,23 @@ export function SettingsProvider({ children }: { children: ReactNode }) {
    return stored ?? 25;
  });

+  const [language, setLanguageState] = useState<StoredLanguage>(() => {
+    return getStoredLanguage() ?? "system";
+  });
+
  const setPoolLength = (length: number) => {
    setPoolLengthState(length);
    storage.set("poolLength", length);
  };

+  const setLanguage = (code: StoredLanguage) => {
+    setLanguageState(code);
+    setStoredLanguage(code);
+    i18n.changeLanguage(resolveLanguage(code));
+  };
+
  return (
-    <SettingsContext.Provider value={{ poolLength, setPoolLength }}>
+    <SettingsContext.Provider value={{ poolLength, setPoolLength, language, setLanguage }}>
      {children}
    </SettingsContext.Provider>
  );
@@ -49,7 +49,7 @@ struct WorkoutListView: View {
                        } label: {
                            HStack {
                                VStack(alignment: .leading, spacing: 4) {
-                                    Text(workout.name ?? "Workout")
+                                    Text(workout.name ?? String(localized: "Workout"))
                                        .font(.headline)
                                        .foregroundColor(.primary)
                                    Text("\(workout.sets.reduce(0) { $0 + $1.distancePerRep * $1.repCount })m · \(workout.sets.count) sets")
@@ -73,7 +73,7 @@ struct WorkoutListView: View {
                        ForEach(workoutManager.completedWorkouts.prefix(3)) { workout in
                            HStack {
                                VStack(alignment: .leading, spacing: 2) {
-                                    Text(workout.name ?? "Workout")
+                                    Text(workout.name ?? String(localized: "Workout"))
                                        .font(.subheadline)
                                        .foregroundColor(.primary)
                                    Text(workout.completedAt ?? "")
@@ -0,0 +1,215 @@
+{
+  "sourceLanguage": "en",
+  "strings": {
+    "No workouts yet": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": { "stringUnit": { "state": "translated", "value": "No workouts yet" } },
+        "nl": { "stringUnit": { "state": "translated", "value": "Nog geen workouts" } },
+        "de": { "stringUnit": { "state": "translated", "value": "Noch keine Workouts" } },
+        "fr": { "stringUnit": { "state": "translated", "value": "Aucun entraînement pour le moment" } },
+        "it": { "stringUnit": { "state": "translated", "value": "Nessun allenamento ancora" } },
+        "es": { "stringUnit": { "state": "translated", "value": "Aún no hay entrenamientos" } },
+        "pl": { "stringUnit": { "state": "translated", "value": "Brak treningów" } },
+        "pt": { "stringUnit": { "state": "translated", "value": "Ainda não há treinos" } },
+        "dk": { "stringUnit": { "state": "translated", "value": "Ingen træninger endnu" } }
+      }
+    },
+    "Create a workout on your iPhone to get started": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": { "stringUnit": { "state": "translated", "value": "Create a workout on your iPhone to get started" } },
+        "nl": { "stringUnit": { "state": "translated", "value": "Maak een workout op je iPhone om te beginnen" } },
+        "de": { "stringUnit": { "state": "translated", "value": "Erstelle ein Workout auf deinem iPhone um zu beginnen" } },
+        "fr": { "stringUnit": { "state": "translated", "value": "Créez un entraînement sur votre iPhone pour commencer" } },
+        "it": { "stringUnit": { "state": "translated", "value": "Crea un allenamento sul tuo iPhone per iniziare" } },
+        "es": { "stringUnit": { "state": "translated", "value": "Crea un entrenamiento en tu iPhone para empezar" } },
+        "pl": { "stringUnit": { "state": "translated", "value": "Stwórz trening na swoim iPhone, aby rozpocząć" } },
+        "pt": { "stringUnit": { "state": "translated", "value": "Crie um treino no seu iPhone para começar" } },
+        "dk": { "stringUnit": { "state": "translated", "value": "Opret en træning på din iPhone for at komme i gang" } }
+      }
+    },
+    "Saved Workouts": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": { "stringUnit": { "state": "translated", "value": "Saved Workouts" } },
+        "nl": { "stringUnit": { "state": "translated", "value": "Opgeslagen workouts" } },
+        "de": { "stringUnit": { "state": "translated", "value": "Gespeicherte Workouts" } },
+        "fr": { "stringUnit": { "state": "translated", "value": "Entraînements enregistrés" } },
+        "it": { "stringUnit": { "state": "translated", "value": "Allenamenti salvati" } },
+        "es": { "stringUnit": { "state": "translated", "value": "Entrenamientos guardados" } },
+        "pl": { "stringUnit": { "state": "translated", "value": "Zapisane treningi" } },
+        "pt": { "stringUnit": { "state": "translated", "value": "Treinos guardados" } },
+        "dk": { "stringUnit": { "state": "translated", "value": "Gemte træninger" } }
+      }
+    },
+    "Workout": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": { "stringUnit": { "state": "translated", "value": "Workout" } },
+        "nl": { "stringUnit": { "state": "translated", "value": "Workout" } },
+        "de": { "stringUnit": { "state": "translated", "value": "Workout" } },
+        "fr": { "stringUnit": { "state": "translated", "value": "Entraînement" } },
+        "it": { "stringUnit": { "state": "translated", "value": "Allenamento" } },
+        "es": { "stringUnit": { "state": "translated", "value": "Entrenamiento" } },
+        "pl": { "stringUnit": { "state": "translated", "value": "Trening" } },
+        "pt": { "stringUnit": { "state": "translated", "value": "Treino" } },
+        "dk": { "stringUnit": { "state": "translated", "value": "Træning" } }
+      }
+    },
+    "Recent": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": { "stringUnit": { "state": "translated", "value": "Recent" } },
+        "nl": { "stringUnit": { "state": "translated", "value": "Recent" } },
+        "de": { "stringUnit": { "state": "translated", "value": "Zuletzt" } },
+        "fr": { "stringUnit": { "state": "translated", "value": "Récent" } },
+        "it": { "stringUnit": { "state": "translated", "value": "Recenti" } },
+        "es": { "stringUnit": { "state": "translated", "value": "Reciente" } },
+        "pl": { "stringUnit": { "state": "translated", "value": "Ostatnie" } },
+        "pt": { "stringUnit": { "state": "translated", "value": "Recente" } },
+        "dk": { "stringUnit": { "state": "translated", "value": "Seneste" } }
+      }
+    },
+    "Sets": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": { "stringUnit": { "state": "translated", "value": "Sets" } },
+        "nl": { "stringUnit": { "state": "translated", "value": "Sets" } },
+        "de": { "stringUnit": { "state": "translated", "value": "Sets" } },
+        "fr": { "stringUnit": { "state": "translated", "value": "Séries" } },
+        "it": { "stringUnit": { "state": "translated", "value": "Serie" } },
+        "es": { "stringUnit": { "state": "translated", "value": "Series" } },
+        "pl": { "stringUnit": { "state": "translated", "value": "Serie" } },
+        "pt": { "stringUnit": { "state": "translated", "value": "Séries" } },
+        "dk": { "stringUnit": { "state": "translated", "value": "Sæt" } }
+      }
+    },
+    "Start": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": { "stringUnit": { "state": "translated", "value": "Start" } },
+        "nl": { "stringUnit": { "state": "translated", "value": "Start" } },
+        "de": { "stringUnit": { "state": "translated", "value": "Starten" } },
+        "fr": { "stringUnit": { "state": "translated", "value": "Commencer" } },
+        "it": { "stringUnit": { "state": "translated", "value": "Inizia" } },
+        "es": { "stringUnit": { "state": "translated", "value": "Iniciar" } },
+        "pl": { "stringUnit": { "state": "translated", "value": "Rozpocznij" } },
+        "pt": { "stringUnit": { "state": "translated", "value": "Iniciar" } },
+        "dk": { "stringUnit": { "state": "translated", "value": "Start" } }
+      }
+    },
+    "Back": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": { "stringUnit": { "state": "translated", "value": "Back" } },
+        "nl": { "stringUnit": { "state": "translated", "value": "Terug" } },
+        "de": { "stringUnit": { "state": "translated", "value": "Zurück" } },
+        "fr": { "stringUnit": { "state": "translated", "value": "Retour" } },
+        "it": { "stringUnit": { "state": "translated", "value": "Indietro" } },
+        "es": { "stringUnit": { "state": "translated", "value": "Volver" } },
+        "pl": { "stringUnit": { "state": "translated", "value": "Wstecz" } },
+        "pt": { "stringUnit": { "state": "translated", "value": "Voltar" } },
+        "dk": { "stringUnit": { "state": "translated", "value": "Tilbage" } }
+      }
+    },
+    "Complete Lap": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": { "stringUnit": { "state": "translated", "value": "Complete Lap" } },
+        "nl": { "stringUnit": { "state": "translated", "value": "Baan voltooien" } },
+        "de": { "stringUnit": { "state": "translated", "value": "Bahn abschließen" } },
+        "fr": { "stringUnit": { "state": "translated", "value": "Terminer la longueur" } },
+        "it": { "stringUnit": { "state": "translated", "value": "Completa lunghezza" } },
+        "es": { "stringUnit": { "state": "translated", "value": "Completar largo" } },
+        "pl": { "stringUnit": { "state": "translated", "value": "Ukończ długość" } },
+        "pt": { "stringUnit": { "state": "translated", "value": "Completar comprimento" } },
+        "dk": { "stringUnit": { "state": "translated", "value": "Fuldfør bane" } }
+      }
+    },
+    "End": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": { "stringUnit": { "state": "translated", "value": "End" } },
+        "nl": { "stringUnit": { "state": "translated", "value": "Einde" } },
+        "de": { "stringUnit": { "state": "translated", "value": "Beenden" } },
+        "fr": { "stringUnit": { "state": "translated", "value": "Terminer" } },
+        "it": { "stringUnit": { "state": "translated", "value": "Fine" } },
+        "es": { "stringUnit": { "state": "translated", "value": "Finalizar" } },
+        "pl": { "stringUnit": { "state": "translated", "value": "Koniec" } },
+        "pt": { "stringUnit": { "state": "translated", "value": "Fim" } },
+        "dk": { "stringUnit": { "state": "translated", "value": "Slut" } }
+      }
+    },
+    "Rest": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": { "stringUnit": { "state": "translated", "value": "Rest" } },
+        "nl": { "stringUnit": { "state": "translated", "value": "Rust" } },
+        "de": { "stringUnit": { "state": "translated", "value": "Pause" } },
+        "fr": { "stringUnit": { "state": "translated", "value": "Repos" } },
+        "it": { "stringUnit": { "state": "translated", "value": "Recupero" } },
+        "es": { "stringUnit": { "state": "translated", "value": "Descanso" } },
+        "pl": { "stringUnit": { "state": "translated", "value": "Odpoczynek" } },
+        "pt": { "stringUnit": { "state": "translated", "value": "Descanso" } },
+        "dk": { "stringUnit": { "state": "translated", "value": "Hvile" } }
+      }
+    },
+    "Lap detected!": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": { "stringUnit": { "state": "translated", "value": "Lap detected!" } },
+        "nl": { "stringUnit": { "state": "translated", "value": "Baan gedetecteerd!" } },
+        "de": { "stringUnit": { "state": "translated", "value": "Bahn erkannt!" } },
+        "fr": { "stringUnit": { "state": "translated", "value": "Longueur détectée !" } },
+        "it": { "stringUnit": { "state": "translated", "value": "Lunghezza rilevata!" } },
+        "es": { "stringUnit": { "state": "translated", "value": "¡Largo detectado!" } },
+        "pl": { "stringUnit": { "state": "translated", "value": "Wykryto długość!" } },
+        "pt": { "stringUnit": { "state": "translated", "value": "Comprimento detectado!" } },
+        "dk": { "stringUnit": { "state": "translated", "value": "Bane registreret!" } }
+      }
+    },
+    "m pool": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": { "stringUnit": { "state": "translated", "value": "%@m pool" } },
+        "nl": { "stringUnit": { "state": "translated", "value": "%@m bad" } },
+        "de": { "stringUnit": { "state": "translated", "value": "%@m Becken" } },
+        "fr": { "stringUnit": { "state": "translated", "value": "Bassin de %@m" } },
+        "it": { "stringUnit": { "state": "translated", "value": "Piscina di %@m" } },
+        "es": { "stringUnit": { "state": "translated", "value": "Piscina de %@m" } },
+        "pl": { "stringUnit": { "state": "translated", "value": "Basen %@m" } },
+        "pt": { "stringUnit": { "state": "translated", "value": "Piscina de %@m" } },
+        "dk": { "stringUnit": { "state": "translated", "value": "%@m pool" } }
+      }
+    },
+    "m total": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": { "stringUnit": { "state": "translated", "value": "%@m total" } },
+        "nl": { "stringUnit": { "state": "translated", "value": "%@m totaal" } },
+        "de": { "stringUnit": { "state": "translated", "value": "%@m gesamt" } },
+        "fr": { "stringUnit": { "state": "translated", "value": "%@m au total" } },
+        "it": { "stringUnit": { "state": "translated", "value": "%@m totale" } },
+        "es": { "stringUnit": { "state": "translated", "value": "%@m total" } },
+        "pl": { "stringUnit": { "state": "translated", "value": "%@m łącznie" } },
+        "pt": { "stringUnit": { "state": "translated", "value": "%@m total" } },
+        "dk": { "stringUnit": { "state": "translated", "value": "%@m i alt" } }
+      }
+    },
+    "kcal": {
+      "extractionState": "manual",
+      "localizations": {
+        "en": { "stringUnit": { "state": "translated", "value": "%@kcal" } },
+        "nl": { "stringUnit": { "state": "translated", "value": "%@kcal" } },
+        "de": { "stringUnit": { "state": "translated", "value": "%@kcal" } },
+        "fr": { "stringUnit": { "state": "translated", "value": "%@kcal" } },
+        "it": { "stringUnit": { "state": "translated", "value": "%@kcal" } },
+        "es": { "stringUnit": { "state": "translated", "value": "%@kcal" } },
+        "pl": { "stringUnit": { "state": "translated", "value": "%@kcal" } },
+        "pt": { "stringUnit": { "state": "translated", "value": "%@kcal" } },
+        "dk": { "stringUnit": { "state": "translated", "value": "%@kcal" } }
+      }
+    }
+  }
+}
@@ -24,7 +24,6 @@ struct SwimView: View {
               workoutManager.currentSetIndex < workout.sets.count {
                let currentSet = workout.sets[workoutManager.currentSetIndex]

-                // Set/Rep info
                HStack {
                    Text("Set \(workoutManager.currentSetIndex + 1)/\(workout.sets.count)")
                        .font(.caption2)
@@ -36,18 +35,15 @@ struct SwimView: View {
                        .foregroundColor(.secondary)
                }

-                // Stroke name
                Text(currentSet.stroke)
                    .font(.headline)
                    .foregroundColor(.cyan)

-                // Current set distance
                Text("\(Int(workoutManager.currentSetDistanceSwum))/\(Int(workoutManager.currentSetTotalDistance))m")
                    .font(.system(size: 36, weight: .bold, design: .rounded))
                    .foregroundColor(.cyan)
            }

-            // Total distance
            HStack(spacing: 4) {
                Image(systemName: "figure.pool.swim")
                    .font(.caption)
@@ -57,11 +53,9 @@ struct SwimView: View {
                    .foregroundColor(.secondary)
            }

-            // Elapsed time
            Text(formatTime(workoutManager.elapsedSeconds))
                .font(.system(.title3, design: .monospaced))

-            // Calories + Heart rate
            HStack(spacing: 12) {
                HStack(spacing: 4) {
                    Image(systemName: "flame.fill")
@@ -82,7 +76,6 @@ struct SwimView: View {
                }
            }

-            // Lap detection indicator
            if workoutManager.lapDetected {
                Text("Lap detected!")
                    .font(.caption)
@@ -138,7 +131,6 @@ struct RestView: View {
                    .foregroundColor(.secondary)
            }

-            // Show stats during rest too
            HStack(spacing: 12) {
                HStack(spacing: 4) {
                    Image(systemName: "figure.pool.swim")
@@ -8,7 +8,7 @@ struct WorkoutDetailView: View {
            if let workout = workoutManager.selectedWorkout {
                Section {
                    VStack(spacing: 8) {
-                        Text(workout.name ?? "Workout")
+                        Text(workout.name ?? String(localized: "Workout"))
                            .font(.headline)

                        Text("\(Int(workout.poolLength))m pool")
@@ -12,7 +12,8 @@
      "@constants/*": ["./src/constants/*"],
      "@db/*": ["./src/db/*"],
      "@navigation/*": ["./src/navigation/*"],
-      "@types/*": ["./src/types/*"]
+      "@types/*": ["./src/types/*"],
+      "@i18n/*": ["./src/i18n/*"]
    }
  },
  "include": ["**/*.ts", "**/*.tsx", "nativewind-env.d.ts"]