instatube
This app is now completely useless since you simply cannot listen to music without a internet connection, I hope that the developers will find a way to go around Youtubes API and let all the users be able to enjoy as much music as possible. I give one star only for the fact that this was a great app once and hopefully will be again.
Balthamort about
Instatube - Video Player for YouTube, Vimeo & Dailymotion, v5.1