YouTube TV app for iOS now has ability to push content to the Apple TV.
The Android version of the mobile app can cast video to Chromecast-enabled TVs.
The new version of YouTube TV for iOS adds AirPlay, allowing iPhone owners to view YouTube TV programming on their television set through the Apple TV.
YouTube TV for iOS is free to download from the iTunes App Store, but the availability of the service is limited to few US markets at this time.