The day we get a good official YouTube app for Windows Phone is the day pigs fly. In the meantime we rely on solid third-party apps like myTube and Metrotube. You’ll be able to add another app to that list very soon. Toib is an upcoming application for YouTube that’s currently in beta. You can join that beta and you really should. It’s a great app with a lot of potential. Variety is the spice of life after all.