As reported by WPCentral the official YouTube app is back in the store with new features!
According to the app description, the features include:
Pin any video, playlist, channel, and search queries to Live Tiles
Manage your YouTube profile with your unique My YouTube page
Manage your playlists, uploads, and video lists
Find channels, videos, and playlists with the quick access search bar
Share videos to your social networks, e-mail, and text messages
Let your kids watch safe videos in Kid’s Corner and keep their own profile
The app is now available for older devices too, which is a great win for legacy users who have felt left out lately from Microsoft’s releases.
You can download the now official (and legal) YouTube app for Windows Phone here in the Store.