I've tried it for better controls of video player, a.e. play/pause, frame-step, free AR selection, frame-snapshot functions, permanent (non hiding automaticly) controls.
NEITHER of this are available for Android version, thus making this extension completely useless, that's why I gave lowest raiting and uninstalled it.
I hope, author will make changes for adopting extension for android users, so I'll be happy to try it again and change rating.