In my opinion, having the "NavigationBar" element included natively in react-native itself would be essential. Why not try to open a PR with this feature in react-native?
Some references: react-native-community/discussions-and-proposals#279
It would probably be the kind of thing that React Native don't want so they don't need to worry about supporting RN non-trivial components, keeping focus on "engine stuff".
In my opinion, having the "NavigationBar" element included natively in react-native itself would be essential. Why not try to open a PR with this feature in react-native?
Some references: react-native-community/discussions-and-proposals#279