First impression of it is a nice interface, but very poor navigation. It just locked up my bold starting a video, so I havent been able to test that yet.
I tried it but it has confusing layout, and the buttons at the bottom are too damn small. the videos aren't better either... IMO the app isn't worth it, the web launcher for m.youtube.com is better... maybe if it had a more conventional layout, and an actual menu box.