That's not from the iOS 8.4 update.
If you swipe up, all the controls disappear. Swipe down to make them reappear.
Cool! I only discovered it by accident, after the latest Pilot update!This has always been the case on the iPad.
Good advice. Still, it would be helpful to share these little Easter Eggs that are undocumented and very useful, in case one of us discovers something more obscure, or less intuitive. "Hey! Look what I found!"I am not sure if there is one, haven't seen one. When I get a new app like this I go thru EVERY screen and option to make sure that I understand what I have. As the iPad is a touch device it is only common sense to swipe every screen to see if there is a function you missed.