Well this would be amazing. Devil's advocate: what about gloves and stylus?I would love it if it worked on the full display, and was on all the time. Use FaceID to unlock the device (as it's more secure than TouchID) and then use TouchID to authenticate every single touch on the screen. So that even if someone grabbed your unlocked phone from your hand, they would only be able to see what is on the screen at that time, but not be able to interact with it in any way.