The YouTube app on the iPhone is great for browsing videos, but it lacks any account integration. There’s just no easy way to see videos that you’ve marked as “Favorite” on YouTube. YouTube Favorites changes that. You now have one-tap access to all your YouTube favorites so you can watch them any time, anywhere.
Please note - youll need to allow access to your favorites in the Privacy/Recent Activity settings on YouTubes site for the app to have access to them (its enabled by default).