BIEL Mobile App

Expo (SDK 55) app using Expo Router with routes in src/app/.

Prerequisites

• Node.js
• pnpm
• Android platform tools (adb on your PATH)
• Expo Go on your Android device (for development without a custom dev build)

Install dependencies

pnpm install

Run on Android (USB device)

Use this flow when your phone is connected over USB and you develop with Expo Go.

1. Connect the device and forward Metro’s port

adb devices
adb reverse tcp:8081 tcp:8081

adb reverse lets the phone reach Metro on your PC at 127.0.0.1:8081. Run it again after unplugging the device or rebooting the phone.

Verify the forward is active:

adb reverse --list

You should see tcp:8081 tcp:8081.

2. Start Metro and open the app on Android

pnpm start --android --localhost

Use --localhost for USB development. The terminal should show a URL like exp://127.0.0.1:8081, not a LAN address such as exp://192.168.x.x:8081.

3. Wait for the first bundle

The first Android bundle often takes 20–35 seconds. Expo Go shows a spinner until Metro logs something like:

Android Bundled ... node_modules/expo-router/entry.js

Later reloads are much faster. This is normal, not necessarily a hang.

4. Reload after code changes

• Shake the device → Reload, or
• Press r in the Metro terminal