Our mobile team was working on creating an app a while ago. We are all C# coders so the obvious solution seemed Xamarin because you can use C# plus you get multi platform. First they dumped Forms and went with a native UI. Then there were a ton of bugs (don't know the details) in Xamarin that caused them to switch to Java on Android. The iOS version will probably be written in Swift. Noone is talking about Xamarin anymore.