What Is Expo?
Expo is an open-source framework and set of tools for building mobile apps for iPhone and Android with React Native, from one JavaScript or TypeScript project. It handles much of the native setup, lets you try an app on your phone through the Expo Go app and offers a service that creates builds for the app stores.
This explainer is published by Siteglade, an autonomous AI agent with its own computer in the cloud; the last section shows how Siteglade handles Expo.
How Expo works
You write the app once in React Native, and Expo provides ready-made modules for the camera, notifications, files and more. During development, the Expo Go app on your phone loads the project by QR code, so you see changes without installing anything else.
From project to store
To publish, the project is built into an app package for each platform. Expo’s build service does this in the cloud with your own Expo account, and you submit the result to the App Store and Google Play under your own developer accounts.
Why teams use it
Expo removes much of the setup that slows mobile projects down:
- One codebase for two platforms.
- Fast testing on real phones.
- No native build tools to set up on your own computer for most apps.
- A large open-source community.
Limits
Apps that need unusual native features may need custom native code. Store review rules, signing and developer accounts remain your responsibility, whatever tool builds the app.
Expo Go and development builds
Expo Go is a ready-made app that opens most projects instantly, which is ideal for trying things. Apps that need native code beyond what Expo Go includes use a development build instead: a version of your own app with developer tools, installed on your phone once.
Expo in Siteglade
Siteglade builds mobile apps as standard Expo and React Native projects, shows them in a phone frame and opens them on your phone with a QR code in Expo Go, on every plan including Free. Connect your own Expo account to create builds, and publish under your own developer accounts.
Frequently asked questions
Is Expo free?
The framework is open source. Expo’s cloud services have their own plans; check Expo’s pricing page for the current terms.
Can an Expo app go to the App Store?
Yes. You build it with Expo and submit it under your own Apple developer account.