Native iOS development requires cool languages, like Swift... that you’ll never use anywhere else. The development environment is painful: build tools straight out of the 80's, certificate hell, TestFlight weirdness. And Android development may be even worse! React Native uses tools and languages you already know—JavaScript and React—to build native apps that use real native components. Meanwhile, Expo is a cloud-based app building service that eliminates just about all the native pain points not addressed by React Native itself. Just upload your code and out comes a signed native binary that even supports OTA updates without the App Store. There’s no need to ever touch an Xcode or Android Studio project. You’ll learn the core concepts behind React Native and Expo, peek under the hood of a live example wired up to data and navigation, and see how to build a store-ready app in just a few simple commands.