I have personally made an ios+android react native app that used native maps functionality (google maps from google cloud services in android and apple maps in

I have personally made an ios+android react native app that used native maps functionality (google maps from google cloud services in android and apple maps in ios). Not even using expo all the app was 100% react native EXCEPT the maps it was a bit awkward, but not really a HUGE issue (note this was in 2016, it seems it is easier now to integrate native code and expo today exposes a lot more functionality without needing native code). The main problem is that, for the very specific parts you need to do native you do need native developers (I did the android native part as I was a bit experienced with android native, but we had to get help for the ios part) Honestly the hard part was making ios and android maps feature-compatible. We wanted heatmaps and apple maps and google maps have completely different algorithms to render heatmaps