[Coda]

Ah, don't do that. :P Hold your phone in both hands and use your thumbs, as if it were a game controller. (Because it is!)

Of course then you're in trouble when you have to press all three at once... my current approach to that is to hold it in my left hand, use my left thumb and right index finger for most of the song, and my left thumb, right index finger, and right middle finger when I need to hit all three.