When playing the piano, very often it would be handy (pun most definitely intended) not to have to reach away from the keyboard when getting to the end of a page of music. Hence, the existence of that most highly-sought job in the classical music world, the page turner...
PageTurn lets you keep your hands where they need to be. It takes a little getting used to, but no more so than adjusting to screen-tapping over physical pages.
PageTurn uses ARKit to track a user's facial expressions, and watches out for gestures which are set to trigger page turns. By default, the app watches for mouth 'twitches' – left to go back a page, right to go forward.
This method strikes an ideal balance between ease, subtlety and intentionality. You can switch to winking if you prefer, though. It's not so subtle, but might suit people with difficulty performing the other option. I'm also going to experiment with adding more gestures soon. You can adjust sensitivity and make other tweaks to get it to exactly suit your face, too.
There's some nice feedback when making gestures, too. Two arrows move in sync with your mouth; when one hits the dot, the page turns. Here's a glimpse of that in action:
With ARKit's facial tracking, the app performs really smoothly, and is extremely accurate. One downside of this approach, unfortunately, is that it limits the app's core features to the current-generation iPad Pro, and the X-series iPhones, so just be aware of that when purchasing.