Gave it a try on both Windows 10 and Android Lollipop.
I was pleasantly surprised to find it automatically detected my vanilla Osu! beatmaps.
Another thing I really liked, specific to the Android version, was that you could play by holding a finger down as you would a tablet, tapping with your other fingers to click. This actually made streams possible on a touch screen, which was a very nice touch.
My only complaint is the lack of a sensitivity option on Windows, though it certainly isn't gamebreaking in the slightest.
All in all, I like it!