Thanks to Expo, running your app in the Xcode simulator only takes a few clicks. To avoid potential issues, it's easiest to make sure your simulator is already running before you attempt to open an Expo-based React Native app in a simulator:
- Open Xcode.
- Open the Simulator from the menu bar: Xcode | Open Developer Tool | Simulator:
- Wait until the simulator has loaded the operating system:
- In the Expo Developer Tools browser window, select Run on iOS Simulator.
- The first time you run a React Native ...