This is an example project that runs in both Expo client and also directly from a build in Xcode/Android studio. Some people want to have the benefits of being able to work on and quickly share their app with the Expo client app, but they need some native modules that aren't available in it. So it's possible to structure your app in a way where if a native module you use isn't present, it falls back to some other behavior (maybe it renders nothing if its a view, or noops / returns some mocked response if it's a function/constant/whatever).
yarn
in the rootcd ios && pod install
expo start
in the root and open it in client