# Expo applications
Prepare your environment by following the [Expo CLI Quickstart instruction](https://reactnative.dev/docs/environment-setup).
For correct work with Expo this extension **`requires Android SDK`**.
So also pay attention to the `React Native CLI Quickstart` tab, where you can find the Android SDK installation guide:

- Install the [Expo app](https://docs.expo.dev/get-started/installation/#2-expo-go-app-for-ios-and) on the target device or emulator
- Ensure that the `Android SDK` is installed on your computer (You may install it using the [`React Native CLI Quickstart` guide](https://reactnative.dev/docs/environment-setup))
- Ensure that the `expo-cli` is installed globally (`npm install -g expo-cli`)

You can verify that everything is working correctly and that the environment is ready for use with the `npx react-native doctor` command.