Tip: remove the jFX object from the class. It will then be cross platform compatible. And the 'ignore comments are not required.
The problem with the animation happens because the PreserveRatio property of the ImageView is set to True. So the image is scaled automatically. Set it to False and it should work.
In newer versions of B4A (v7.8), B4J (v6.0) and B4i (not yet released) it is simple to share code modules between projects, including projects targeting other platforms.