iTube allows you to organize youtube videos in playlists, view history of watched videos and bookmark videos.
– Play Top 100 songs or top 100 from different generes.
– Manage playlists: Create, rename or delete.
– Search music videos by keyword.
– Rotate to full screen play mode.
– Skip songs with headphones or iPod controls.
– Double Tap on video to zoom in and out, one tap to dismiss controls.
– Works on background.
– Display media info on lock screen (iOS 5+).
– Lyrics button (when a available)
– Sleep timer: scroll player controls to the left
– Multiple action on playlist: delete and add to playlist
– Quick automatic search on history, favorites and playlists
Read more here: iTube FREE – Playlist Manager for YouTube PRO – Valeria Medina