YouTube Remote app for Android creates a virtual connection between your phone and YouTube Leanback. "To "pair" your phone with Leanback screen, simply sign into YouTube Remote on Android, and to YouTube Leanback on your Google TV or computer with same YouTube account. Just like that, you've connected your Android screen with the biggest screen in your home.
Once connected, you can use the rich browse and discovery interface on YouTube Remote to find and queue up videos to watch, and send them all to Leanback with a single tap. With YouTube Remote you can play, pause, skip forward and back and even control the sound volume," explains Google.
Again, you can download YouTube Remote now on the Android Marketplace.