Many developers struggle with installing and configuring React Native’s current native build dependencies, especially for Android. With Create React Native App, there’s no need to use Xcode or Android Studio, and you can develop for your iOS device using Linux or Windows. This is accomplished using the Expo app, which loads and runs CRNA projects written in pure JavaScript without compiling any native code.
https://facebook.github.io/react-native/blog/2017/03/13/introducing-create-react-native-app.html
Lets web developers build truly native apps that work across both iOS and Android by writing them once in just JavaScript.
It’s open source and free and uses React Native.
https://expo.io/