This is an example React Native Expo App supporting Android, iOS, Web, and Electron desktop apps.

1. brew cask install adoptopenjdk/openjdk/adoptopenjdk8 android-studio ngrok

2. yarn install

3. (Optional) Open Android Studio

   1. Follow the wizard to create a blank project
   2. Wait for the app to finish building
   3. Click Build > Generate Signed Bundle / APK > Next > Create new...
   4. Enter some application details and save as keystore.jks in this folder

4. (Optional) Open Xcode

   1. Click Xcode > Preferences
   2. Click Account, add an Apple account
   3. Manage Certificates... > Generate a new developer certificate

5. (Optional) For production apps:

   cat >> .env <<EOL # Replace <var> with your details from steps above # Deployed `dist` folder or run `yarn serve:dist` to do this automatically export EXPO_APP_PUBLIC_URL="https://<Your ID>.ngrok.io" # Deployed `dist-electron` folder or run `yarn serve:electron:dist` to do this automatically export EXPO_ELECTRON_PUBLIC_URL="https://<Your ID>.ngrok.io" # From Android Studio step above export EXPO_ANDROID_KEYSTORE_PASSWORD="<Your 1st Password>" export EXPO_ANDROID_KEY_PASSWORD="<Your 2nd Password>" export EXPO_ANDROID_KEYSTORE_ALIAS="<Your Key Alias e.g key0>" EOL 

For Android, iOS, and Web:

yarn start 

For the Electron desktop app:

yarn electron 

Build Android APK:

# First tab (if `dist` folder is not deployed online) yarn serve:dist # Update `.env` file with displayed ngrok domain # Second tab, outputs APK to: `~/expo-apps` yarn android:build # Copy to phone and install check that it works, then bump the version number in `package.json` yarn build # Relaunch the app, check ngrok logs to see if app it downloading the latest bundle, restart app to apply update 

Build Electron desktop app:

# First tab: to serve the `dist-electron` folder (if not deployed online) yarn serve:electron:dist # Second tab, outputs to: `dist/mac` yarn electron:build:packed # Install via the `dmg` file, bump the version number in `package.json` and rerun the `electron:build:packed` command above # Watch the update being downloaded via /Applications/react_native_android_ios_web_electron.app/Contents/MacOS/react_native_android_ios_web_electron 

Build Web app:

# Outputs to: `web-build` yarn web:build # Run server yarn serve web-build