Presumably yes if it uses native APIs. On iOS, although .nib files are supported, people tend to prefer Ruby DSLs to define interfaces though. I imagine that so

Presumably yes if it uses native APIs. On iOS, although .nib files are supported, people tend to prefer Ruby DSLs to define interfaces though. I imagine that something similar will happen on Android. Expect that it won't be long before somebody comes out with a cross-platform wrapper for native UI elements similar to Xamarin 3.0.