Through the open source JavaFXPorts project, most of the JavaFX 8u40 API’s are supported on Android. Performance seems to be comparable with native Android applications. The JavaFX SDK is using the same codebase as the JavaFX SDK for desktop platforms.
With the forthcoming Gluon Mobile library, JavaFX on Android will be far improved, as we will provide API to more simply create user interfaces that mimic the look of the latest Android material UI guidelines. On top of this, we plan to provide deeper integration into the various hardware features of the various mobile devices.