diff --git a/.gitignore b/.gitignore
index 6c2d460..30ec341 100644
--- a/.gitignore
+++ b/.gitignore
@@ -36,3 +36,12 @@ src-tauri/target/
 .expo/
 .expo-shared/
 *.tsbuildinfo
+
+# Android
+android/app/build/
+android/.gradle/
+android/build/
+*.hprof
+*.jks
+*.keystore
+local.properties
diff --git a/package.json b/package.json
new file mode 100644
index 0000000..bdea7ec
--- /dev/null
+++ b/package.json
@@ -0,0 +1,10 @@
+{
+  "name": "yuzu-gca",
+  "private": true,
+  "version": "0.1.0",
+  "description": "Global Control Assistant — 全局控制助手",
+  "scripts": {
+    "android": "pnpm --filter @yuzu-gca/client-android start",
+    "build:android": "pnpm --filter @yuzu-gca/client-android build"
+  }
+}
diff --git a/packages/client-android/App.tsx b/packages/client-android/App.tsx
new file mode 100644
index 0000000..8c4629e
--- /dev/null
+++ b/packages/client-android/App.tsx
@@ -0,0 +1,72 @@
+import { StatusBar } from 'expo-status-bar';
+import { useEffect, useState } from 'react';
+import { StyleSheet, Text, View, ActivityIndicator } from 'react-native';
+import { onAppStartCheckUpdate } from './src/updater/index';
+
+export default function App() {
+  const [status, setStatus] = useState<'checking' | 'up-to-date' | 'updating' | 'error'>('checking');
+  const [message, setMessage] = useState('正在检查更新...');
+
+  useEffect(() => {
+    (async () => {
+      try {
+        const result = await onAppStartCheckUpdate();
+        if (result.jsUpdate) {
+          setStatus('updating');
+          setMessage('发现 JS 更新，正在下载...（下次启动生效）');
+        } else if (result.apkUpdate) {
+          setStatus('updating');
+          setMessage('安装包已就绪，重启后生效');
+        } else {
+          setStatus('up-to-date');
+          setMessage('已是最新版本');
+        }
+      } catch (e: any) {
+        setStatus('error');
+        setMessage(`更新检查失败: ${e.message}`);
+      }
+    })();
+  }, []);
+
+  return (
+    <View style={styles.container}>
+      <StatusBar style="light" />
+      <Text style={styles.title}>Yuzu GCA</Text>
+      <Text style={styles.subtitle}>Global Control Assistant</Text>
+      <View style={styles.statusBar}>
+        {status === 'checking' && <ActivityIndicator color="#3b82f6" />}
+        <Text style={styles.statusText}>{message}</Text>
+      </View>
+    </View>
+  );
+}
+
+const styles = StyleSheet.create({
+  container: {
+    flex: 1,
+    backgroundColor: '#0f172a',
+    alignItems: 'center',
+    justifyContent: 'center',
+    padding: 24,
+  },
+  title: {
+    fontSize: 28,
+    fontWeight: '800',
+    color: '#e2e8f0',
+    marginBottom: 4,
+  },
+  subtitle: {
+    fontSize: 14,
+    color: '#94a3b8',
+    marginBottom: 32,
+  },
+  statusBar: {
+    flexDirection: 'row',
+    alignItems: 'center',
+    gap: 8,
+  },
+  statusText: {
+    fontSize: 14,
+    color: '#94a3b8',
+  },
+});
diff --git a/packages/client-android/app.json b/packages/client-android/app.json
new file mode 100644
index 0000000..12291d4
--- /dev/null
+++ b/packages/client-android/app.json
@@ -0,0 +1,42 @@
+{
+  "expo": {
+    "name": "YuzuGCA",
+    "slug": "yuzu-gca",
+    "version": "0.1.0",
+    "orientation": "portrait",
+    "icon": "./assets/icon.png",
+    "userInterfaceStyle": "dark",
+    "newArchEnabled": true,
+    "splash": {
+      "backgroundColor": "#0f172a"
+    },
+    "ios": {
+      "supportsTablet": false,
+      "bundleIdentifier": "dev.yuzu.gca"
+    },
+    "android": {
+      "adaptiveIcon": {
+        "backgroundColor": "#0f172a"
+      },
+      "package": "dev.yuzu.gca",
+      "allowBackup": false,
+      "permissions": [
+        "REQUEST_INSTALL_PACKAGES"
+      ]
+    },
+    "plugins": [
+      "expo-updates"
+    ],
+    "updates": {
+      "enabled": true,
+      "checkAutomatically": "ON_LOAD",
+      "fallbackToCacheTimeout": 0,
+      "url": "https://git.childish-ghost.com/LukeMackin/Yuzu-GCA/releases/download/manifest/expo-manifest.json"
+    },
+    "extra": {
+      "eas": {
+        "projectId": "yuzu-gca-android"
+      }
+    }
+  }
+}
diff --git a/packages/client-android/manifest.json b/packages/client-android/manifest.json
new file mode 100644
index 0000000..3503790
--- /dev/null
+++ b/packages/client-android/manifest.json
@@ -0,0 +1,12 @@
+{
+  "version": "0.1.0",
+  "builds": {
+    "android": {
+      "tag": "v0.1.0-dav-android-1",
+      "url": "https://git.childish-ghost.com/LukeMackin/Yuzu-GCA/releases/download/v0.1.0-dav-android-1/gca-0.1.0.apk",
+      "sha256": "PLACEHOLDER",
+      "size": 0,
+      "minVersion": "0.1.0"
+    }
+  }
+}
diff --git a/packages/client-android/modules/package-installer/android/src/main/java/dev/yuzu/gca/PackageInstallerModule.kt b/packages/client-android/modules/package-installer/android/src/main/java/dev/yuzu/gca/PackageInstallerModule.kt
new file mode 100644
index 0000000..b5ef34a
--- /dev/null
+++ b/packages/client-android/modules/package-installer/android/src/main/java/dev/yuzu/gca/PackageInstallerModule.kt
@@ -0,0 +1,55 @@
+package dev.yuzu.gca
+
+import android.app.PendingIntent
+import android.content.Context
+import android.content.Intent
+import android.content.pm.PackageInstaller
+import expo.modules.kotlin.modules.Module
+import expo.modules.kotlin.modules.ModuleDefinition
+import java.io.File
+import java.io.FileInputStream
+
+class PackageInstallerModule : Module() {
+    override fun definition() = ModuleDefinition {
+        Name("PackageInstallerModule")
+
+        AsyncFunction("installApk") { filePath: String ->
+            installApk(filePath)
+        }
+    }
+
+    private fun installApk(filePath: String) {
+        val context: Context = appContext.reactContext ?: return
+        val apkFile = File(filePath)
+        if (!apkFile.exists()) throw Exception("APK file not found: $filePath")
+
+        val packageInstaller = context.packageManager.packageInstaller
+        val sessionParams = PackageInstaller.SessionParams(
+            PackageInstaller.SessionParams.MODE_FULL_INSTALL
+        )
+
+        val sessionId = packageInstaller.createSession(sessionParams)
+        val session = packageInstaller.openSession(sessionId)
+
+        try {
+            FileInputStream(apkFile).use { input ->
+                session.openWrite("package", 0, apkFile.length()).use { output ->
+                    input.copyTo(output)
+                }
+                session.fsync(output)
+            }
+
+            // 安装完成后发送通知，用户点击即重启
+            val intent = Intent(context, context.javaClass)
+            intent.action = Intent.ACTION_MAIN
+            val pendingIntent = PendingIntent.getActivity(
+                context, 0, intent,
+                PendingIntent.FLAG_UPDATE_CURRENT or PendingIntent.FLAG_IMMUTABLE
+            )
+
+            session.commit(pendingIntent.intentSender)
+        } finally {
+            session.close()
+        }
+    }
+}
diff --git a/packages/client-android/modules/package-installer/expo-module.config.json b/packages/client-android/modules/package-installer/expo-module.config.json
new file mode 100644
index 0000000..93f3acd
--- /dev/null
+++ b/packages/client-android/modules/package-installer/expo-module.config.json
@@ -0,0 +1,4 @@
+{
+  "platform": "android",
+  "modules": ["PackageInstallerModule"]
+}
diff --git a/packages/client-android/package.json b/packages/client-android/package.json
new file mode 100644
index 0000000..06be123
--- /dev/null
+++ b/packages/client-android/package.json
@@ -0,0 +1,28 @@
+{
+  "name": "@yuzu-gca/client-android",
+  "version": "0.1.0",
+  "private": true,
+  "main": "expo-router/entry",
+  "scripts": {
+    "start": "expo start",
+    "android": "expo start --android",
+    "build": "eas build -p android --profile preview",
+    "export": "expo export --platform android",
+    "prebuild": "expo prebuild --platform android"
+  },
+  "dependencies": {
+    "@yuzu-gca/shared": "workspace:*",
+    "expo": "~52.0.0",
+    "expo-constants": "~17.0.0",
+    "expo-device": "~7.0.0",
+    "expo-file-system": "~18.0.0",
+    "expo-status-bar": "~2.0.0",
+    "expo-updates": "~26.0.0",
+    "react": "18.3.1",
+    "react-native": "0.76.5"
+  },
+  "devDependencies": {
+    "@types/react": "~18.3.0",
+    "typescript": "^5.5.0"
+  }
+}
diff --git a/packages/client-android/src/updater/index.ts b/packages/client-android/src/updater/index.ts
new file mode 100644
index 0000000..721ef5d
--- /dev/null
+++ b/packages/client-android/src/updater/index.ts
@@ -0,0 +1,111 @@
+import { parseVersion, checkUpdate, semverGt } from '@yuzu-gca/shared';
+import Constants from 'expo-constants';
+import * as Device from 'expo-device';
+import * as FileSystem from 'expo-file-system';
+import { NativeModules, Platform } from 'react-native';
+
+// ============================================================
+// 1. 版本号读取
+// ============================================================
+
+/** 从 app.json + expo-updates 获取本地版本 */
+export function getLocalVersion(): string {
+  return Constants.expoConfig?.version ?? '0.1.0';
+}
+
+export function getLocalBuildTag(): string {
+  const v = getLocalVersion();
+  return `v${v}-dav-android-${Constants.expoConfig?.ios?.buildNumber ?? Constants.expoConfig?.android?.versionCode ?? 1}`;
+}
+
+// ============================================================
+// 2. JS Bundle OTA（expo-updates 自动处理）
+// ============================================================
+
+/** 手动触发 OTA 检查（expo-updates 已自动启动检查，此方法用于设置页手动刷新） */
+export async function checkJsBundleUpdate(): Promise<{
+  hasUpdate: boolean;
+  remoteVersion: string;
+}> {
+  const localVersion = getLocalVersion();
+  const localTag = getLocalBuildTag();
+
+  const result = await checkUpdate('android', parseVersion(localTag)!);
+  if (!result.shouldUpdate || !result.remoteVersion) {
+    return { hasUpdate: false, remoteVersion: localVersion };
+  }
+
+  // expo-updates 会在检测到新 manifest 时自动下载 bundle
+  // 这里只返回状态；实际下载由 expo-updates 后台完成
+  return {
+    hasUpdate: semverGt(result.remoteVersion.raw.replace(/^v/, '').split('-')[0], localVersion),
+    remoteVersion: result.remoteVersion.raw,
+  };
+}
+
+// ============================================================
+// 3. APK 静默安装（大更新）
+// ============================================================
+
+const { PackageInstallerModule } = NativeModules;
+
+/** 后台下载 APK 并通过 PackageInstaller 静默安装 */
+export async function downloadAndInstallApk(apkUrl: string, sha256: string): Promise<void> {
+  const localPath = `${FileSystem.cacheDirectory ?? ''}gca-update.apk`;
+
+  const download = FileSystem.createDownloadResumable(
+    apkUrl,
+    localPath,
+    {},
+    (progress) => {
+      const pct = (progress.totalBytesWritten / progress.totalBytesExpectedToWrite) * 100;
+      console.log(`[OTA] 下载进度: ${pct.toFixed(0)}%`);
+    },
+  );
+
+  const result = await download.downloadAsync();
+  if (!result?.uri) throw new Error('APK 下载失败');
+
+  console.log(`[OTA] 下载完成: ${result.uri}`);
+
+  // 调用原生 PackageInstaller 安装
+  if (Platform.OS === 'android' && PackageInstallerModule) {
+    await PackageInstallerModule.installApk(result.uri);
+    console.log('[OTA] APK 已提交安装，用户下次重启生效');
+  } else {
+    throw new Error('PackageInstaller 原生模块不可用');
+  }
+}
+
+// ============================================================
+// 4. 启动时一键检查（JS OTA + APK 更新）
+// ============================================================
+
+export async function onAppStartCheckUpdate(): Promise<{
+  jsUpdate: boolean;
+  apkUpdate: boolean;
+}> {
+  const localTag = getLocalBuildTag();
+  const local = parseVersion(localTag);
+  if (!local) return { jsUpdate: false, apkUpdate: false };
+
+  const result = await checkUpdate('android', local);
+  if (!result.shouldUpdate || !result.build) {
+    return { jsUpdate: false, apkUpdate: false };
+  }
+
+  // JS OTA: expo-updates 自动处理，无需手动干预
+  const jsUpdate = semverGt(
+    result.build.tag.replace(/^v/, '').split('-')[0],
+    localTag.replace(/^v/, '').split('-')[0],
+  );
+
+  // APK 大更新：需要下载 + PackageInstaller
+  if (result.build.size > 5_000_000) {
+    // >5MB = APK 安装包
+    await downloadAndInstallApk(result.build.url, result.build.sha256);
+    return { jsUpdate: false, apkUpdate: true };
+  }
+
+  return { jsUpdate, apkUpdate: false };
+}
diff --git a/packages/client-android/tsconfig.json b/packages/client-android/tsconfig.json
new file mode 100644
index 0000000..12f7715
--- /dev/null
+++ b/packages/client-android/tsconfig.json
@@ -0,0 +1,16 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "strict": true,
+    "jsx": "react-jsx",
+    "esModuleInterop": true,
+    "skipLibCheck": true,
+    "paths": {
+      "@yuzu-gca/shared": ["../shared/src"]
+    }
+  },
+  "include": ["**/*.ts", "**/*.tsx"],
+  "exclude": ["node_modules"]
+}
diff --git a/packages/shared/package.json b/packages/shared/package.json
new file mode 100644
index 0000000..341d49d
--- /dev/null
+++ b/packages/shared/package.json
@@ -0,0 +1,13 @@
+{
+  "name": "@yuzu-gca/shared",
+  "version": "0.1.0",
+  "private": true,
+  "main": "src/index.ts",
+  "types": "src/index.ts",
+  "scripts": {
+    "typecheck": "tsc --noEmit"
+  },
+  "devDependencies": {
+    "typescript": "^5.5.0"
+  }
+}
diff --git a/packages/shared/src/index.ts b/packages/shared/src/index.ts
new file mode 100644
index 0000000..00434e8
--- /dev/null
+++ b/packages/shared/src/index.ts
@@ -0,0 +1,2 @@
+export { parseVersion, compareVersion, checkUpdate, semverGt } from './updater/index';
+export type { GcaVersion, Manifest, ManifestBuild } from './updater/index';
diff --git a/packages/shared/src/updater/index.ts b/packages/shared/src/updater/index.ts
new file mode 100644
index 0000000..4977116
--- /dev/null
+++ b/packages/shared/src/updater/index.ts
@@ -0,0 +1,82 @@
+/** 版本号解析 vX.Y.Z-dav-{client}-{build} */
+export interface GcaVersion {
+  major: number;
+  minor: number;
+  patch: number;
+  client: 'desktop' | 'android' | 'cli';
+  build: number;
+  raw: string;
+}
+
+export interface Manifest {
+  version: string;
+  builds: Record<string, ManifestBuild>;
+}
+
+export interface ManifestBuild {
+  tag: string;
+  url: string;
+  sha256: string;
+  size: number;
+  minVersion?: string;
+}
+
+const MANIFEST_URL = 'https://git.childish-ghost.com/LukeMackin/Yuzu-GCA/releases/download/manifest/manifest.json';
+
+const VERSION_RE = /^v(\d+)\.(\d+)\.(\d+)-dav-(desktop|android|cli)-(\d+)$/;
+
+export function parseVersion(raw: string): GcaVersion | null {
+  const m = raw.trim().match(VERSION_RE);
+  if (!m) return null;
+  return {
+    major: parseInt(m[1], 10),
+    minor: parseInt(m[2], 10),
+    patch: parseInt(m[3], 10),
+    client: m[4] as GcaVersion['client'],
+    build: parseInt(m[5], 10),
+    raw,
+  };
+}
+
+export function compareVersion(a: GcaVersion, b: GcaVersion): number {
+  if (a.major !== b.major) return a.major - b.major;
+  if (a.minor !== b.minor) return a.minor - b.minor;
+  if (a.patch !== b.patch) return a.patch - b.patch;
+  return a.build - b.build;
+}
+
+/** 调用方传入本地版本号，返回是否需要更新以及目标 manifest entry */
+export async function checkUpdate(
+  client: GcaVersion['client'],
+  localVersion: GcaVersion,
+  manifestUrl = MANIFEST_URL,
+): Promise<{ shouldUpdate: boolean; build: ManifestBuild | null; remoteVersion: GcaVersion | null }> {
+  try {
+    const resp = await fetch(manifestUrl);
+    if (!resp.ok) return { shouldUpdate: false, build: null, remoteVersion: null };
+
+    const manifest: Manifest = await resp.json();
+    const build = manifest.builds[client];
+    if (!build) return { shouldUpdate: false, build: null, remoteVersion: null };
+
+    const remoteVersion = parseVersion(build.tag);
+    if (!remoteVersion) return { shouldUpdate: false, build: null, remoteVersion: null };
+
+    return {
+      shouldUpdate: compareVersion(remoteVersion, localVersion) > 0,
+      build,
+      remoteVersion,
+    };
+  } catch {
+    return { shouldUpdate: false, build: null, remoteVersion: null };
+  }
+}
+
+/** SemVer 比较（用于 expo-updates manifest） */
+export function semverGt(a: string, b: string): boolean {
+  const [aM, am, aP] = a.split('.').map(Number);
+  const [bM, bm, bP] = b.split('.').map(Number);
+  if (aM !== bM) return aM > bM;
+  if (am !== bm) return am > bm;
+  return aP > bP;
+}
diff --git a/packages/shared/tsconfig.json b/packages/shared/tsconfig.json
new file mode 100644
index 0000000..964fbee
--- /dev/null
+++ b/packages/shared/tsconfig.json
@@ -0,0 +1,14 @@
+{
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "ESNext",
+    "moduleResolution": "bundler",
+    "strict": true,
+    "declaration": true,
+    "outDir": "dist",
+    "rootDir": "src",
+    "esModuleInterop": true,
+    "skipLibCheck": true
+  },
+  "include": ["src"]
+}
diff --git a/pnpm-workspace.yaml b/pnpm-workspace.yaml
new file mode 100644
index 0000000..18ec407
--- /dev/null
+++ b/pnpm-workspace.yaml
@@ -0,0 +1,2 @@
+packages:
+  - 'packages/*'