I understand that there is no way to set a user's wallpaper, but the apple program Voice Memos temporarily changes the locked screen while recording. This lets you know that the app is still recording, and even has a little red bar at the top showing you how many seconds have passed.
Is it possible for me to do this while my app is running? I can't seem to find any reference in the documentation.
Is this just one of the benefits of being the author of the OS?