Installing Expo

The Expo project used to have a GUI-based development environment called the Expo XDE, which has been replaced with a browser-based GUI called the Expo Developer Tools. Since the Expo XDE has been deprecated, creating new Expo apps is now always done using the Expo CLI. This can be installed using npm (Node Package Manager, which comes as part of Node.js) via the Terminal with the following command:

 npm install expo-cli -g

We'll be using Expo quite a bit throughout this book to create and build out React Native applications, particularly those apps that do not need access to native iOS or Android code. Applications built with Expo have some very nice advantages for development, helping obfuscate native code, streamlining app publishing and push notifications, and providing a lot of useful functionality built into the Expo SDK. For more information on how Expo works, and how it fits into the bigger picture of React Native development, see Chapter 10, App Workflow and Third-Party Plugins.