Make sure your environment is set up to run react native applications. Follow the instructions here https://facebook.github.io/react-native/docs/getting-started.html to the point you have installed the react-native-cli.
The ReactNative sample project is in the `examples/ReactExample` directory. You must run `npm install` in this directory before running the example for the first time.
- Drag `RealmJS.framework` from the `Products` directory under `RealmJS.xcodeproj` into the `Embedded Libraries` section in the `General` tab for you app's target settings. This bundles the library with your app.