React-native v0.12.0 now comes with support for Android out-of-the-box.

A common issue when writing cross platform (a.k.a isomorphic) code is determining which platform your code is being executed on.

Luckily there's a simple way:

import { Platform } from 'react-native';

if ( Platform.OS === 'ios' ) {
  // iOS specific code here
} else {
  // Android specific code here
}