Multitask during a call. Press the Home button, then tap an app icon. You can still talk with your friend, but you can’t see each other. To return to the video, tap the green bar at the top of the screen.
Take advantage of Favorites. Tap Favorites. To add a favorite, Tap 
, then choose a contact and add to Favorites as FaceTime Audio or FaceTime. To call a favorite, tap a name in the list. Make sure phone numbers for contacts outside your region include the country code and area code.
Juggle calls. FaceTime calls aren’t forwarded. If another call comes in while you’re on a FaceTime call, you can either end the FaceTime call and answer the incoming call, decline the incoming call, or reply with a text message.
Block unwanted callers. Go to Settings > FaceTime > Blocked > Add New. You won’t receive FaceTime calls or text messages from blocked callers. For more information about blocking calls, see support.apple.com/kb/HT5845.
Other options in Settings let you turn FaceTime on or off, specify a phone number, Apple ID, or email address to use with FaceTime, and set your caller ID.