I think the point about visual feedback when a tap registers is really important. On touch devices it is pretty much standard that some % of your taps will fail

I think the point about visual feedback when a tap registers is really important. On touch devices it is pretty much standard that some % of your taps will fail to register, either registering on some other screen element (because mobile UI designers love to make REALLY TINY buttons right next to other touchable elements) or just not registering, perhaps because your finger shifted too much before you lifted it up, or you were off by a couple pixels. So having clear visual feedback that a touch registered, and showing you where it registered, is huge. I reserve a special curse for people who implement touch feedback separate from touch processing, though. I've used a couple different apps where it's possible to create a visual 'touch' that doesn't actually trigger a click on the button, and that's infuriating.