Very good, but a few things.

Amazing app. Offline for free, no paying or anything. It will take up more space as you download more, and no download offline. If you want to take less space, only download large mixes or playlists in one video, it only counts as one song. But, if you are an iPhone 4 user like me, then beware that it may crash if you try to download more than three or so songs at once. Otherwise, it is a great app

Shut up whiners about Free Tube Music - Mp3 Player and Playlist Manager, v1.1.0