Expo

Expo is a platform for building mobile apps with React Native. It provides a command-line tool and development tools for writing the app, Expo Go for testing on a real phone during development, cloud builds that produce iOS and Android binaries, submission to TestFlight and the app stores, and over-the-air updates for changes after release.

React Native lets developers write one codebase in JavaScript or TypeScript with React components and ship native apps for both iOS and Android. Expo removes much of the setup and native build work that React Native projects otherwise need, and Expo's libraries give access to device features such as the camera, notifications and location.

What Expo handles

• Project setup and development tools for React Native
• Testing on devices and simulators during development
• Cloud builds for iOS and Android
• Submission to TestFlight, the App Store and Google Play
• Over-the-air updates with release channels
• Production monitoring of crashes and update adoption

Why over-the-air updates matter

App store releases go through review, which can take time. Expo's update service lets a team ship JavaScript and asset changes, such as a bug fix or a copy change, directly to installed apps without a new store release. Changes to native code still go through a normal store build and review.

When Expo fits

Expo fits businesses that need an iOS and Android app from one codebase: booking apps, member apps, ordering apps and companion apps for an existing web platform. Teams that already use React on the web can share design patterns and some logic. Apps with unusual native requirements may need custom native modules, which Expo supports through development builds.