Code snippet from ReactNav application as featured in http://platypus.is/posts/4

redScreenNavOptions.js

# App.js

...
RedScreen.navigationOptions = props => {
  const { navigation } = props;
  return {
    headerTitle: 'Red',
    headerRight: (<Button title='Purple' onPress={() => navigation.navigate('Purple')}/>),
    headerLeft: (<Button title='Blue' onPress={() => navigation.navigate('Blue')}/>)
  }
}
...