FRITZ!App TV can play back HD channels on all mobile devices with Apple iOS.

For technical reasons, you cannot play back HD channels with FRITZ!App TV on all Android devices. If it is not possible to play back HD channels, no HD channels are displayed in the channel overview and FRITZ!App TV displays the message "HD-Sender werden nicht unterstützt" under "Settings > About FRITZ!App TV". However, you may be able to use a different app to play back the HD channels on the respective device, for example with VLC for Android.