Use lazy requires for screens for React Navigation

LazyLoadComponent.js

//Navigator
const SettingsScreen = createLazyComponent(
  () => require('../containers/component').default
);
// ...
const MainStackNavigator = StackNavigator(
  {
    SettingsScreen: {
      screen: SettingsScreen,

//LazyComponent.js
export default function createLazyComponent<Props>(
  getClass: () => React.ComponentType<Props>
) {
  return class extends React.PureComponent<Props> {
    lazyComponentClass: ?React.ComponentType<Props> = getClass();

    render() {
      const LazyComponent = this.lazyComponentClass;
      if (LazyComponent == null) {
        return null;
      }
      return (
        <LazyComponent {...this.props} />
      );
    }
  };
}

can't u use React.Node for children type?

I think actually unless you need to do something specific with the children, children can be passed implicitly with the prop spread. So no issues with Flow typing.