Code snippets from ReactNativeFirebase application as featured in http://platypus.is/posts/5

importFirebase.js

# firebaseConfig.js

...
import * as firebase from 'firebase';
...

importFirebaseApp.js

# index.ios.js and/or index.android.js

...
import firebaseApp from './firebaseConfig.js';
...

initializeFirebase.js

# firebaseConfig.js

...
// Initialize Firebase
const firebaseConfig = {
  apiKey: "<your-api-key>",
  authDomain: "<your-auth-domain>",
  databaseURL: "<your-database-url>",
  storageBucket: "<your-storage-bucket>"
};
const firebaseApp = firebase.initializeApp(firebaseConfig);

export default firebaseApp;