Apple Photos, Maps and Notes have it (not surprisingly). You have to get used to it, but once you do, it does seem easier to reach for the toolbar and do things directly rather than using a trackpad to find and manipulate a toggle/button/slider or dial on the screen. I'm sure Apple did ergonomics studies on this. Would be interesting see their conclusions and time/motion studies. I'm hoping more apps pick it up, though Apple seems to be having developers and others get on board with their recent innovations (witness the slow uptake on Single Sign On for Apple TV).
