index.js

class MyApp extends Component {
  ...
  render(
    return(
      <View>....</View>
    )
  )
}

//set check frequency options
const codePushOptions = { checkFrequency: codePush.CheckFrequency.ON_APP_START };
const MyApp = codePush(codePushOptions)(MyApp);

AppRegistry.registerComponent('MyApp', () => MyApp);