Get the currently-routed AppleTV's name.

AppleTVName

// Use in conjunction with e.g. KVO on AVPlayer.externalPlaybackActive
AVAudioSessionPortDescription *port = [AVAudioSession sharedInstance].currentRoute.outputs.firstObject;
if ([port.portType isEqualToString:AVAudioSessionPortAirPlay]) {
    NSLog(@"Now playing on '%@'", port.portName);
}