Using YouTube Account Features
If you have a YouTube account, you can access account features such as subscriptions, comments and ratings, and playlists. To create a YouTube account, go to www.youtube.com.
Show favorites you’ve added to your account:
In Favorites, tap Sign In, then enter your username and password to see your account favorites. Any existing favorites you’ve added to iPhone can be merged with your account favorites when you sign in.
Delete a favorite:
In Favorites, tap Edit, tap 
next to a video, then tap Delete.
Show subscriptions you’ve added to your account:
In Subscriptions, tap Sign In, then enter your username and password to see your account subscriptions. Tap an account in the list to see all videos for that account.
Unsubscribe from a YouTube account:
In Subscriptions, tap an account in the list, then tap Unsubscribe.
View playlists:
In Playlists, tap a playlist to see the list of videos you’ve added. Tap any video in the playlist to begin playing videos from that point in the playlist.
Edit a playlist:
In Playlists, tap Edit, then do one of the following:
To delete the entire playlist, tap
next to a playlist, then tap Delete.To create a new playlist, tap
, then enter a name for the playlist.
Add a video to a playlist:
Tap 
next to a video, then tap “Add to Playlist” and choose a playlist.
Delete a video from a playlist:
In Playlists, tap a playlist, then tap Edit.
Tap
next to a playlist, then tap Delete.