There are two buttons (on each controller) that rotate objects by a set amount. Like, 10°/second or something.
It's a big touch button, so I'm thinking, why split it up into two directions?
Let's say the left 'button' was the only rotate button. You press it down and drag your thumb around the touch pad. Dragging your thumb around clockwise would rotate the object clockwise and the same for counter clockwise. That way it frees up a button and you can rotate the object exactly where you want it, instead of waiting for the object to cycle around like you're setting the time on an old clock radio.
I was thinking dragging across instead of rotating could flip the object, to free up another button, but that might make it harder to flip a lot of items in quick succession.