I don't think there's any way to detect input over a large portion of the screen(for example pressing your entire thumb over multiple directions) so I don't think strafing would be possible. I dunno, I might be wrong. I know on my Galaxy S2 it has motions like swiping your entire palm over the screen, but I don't know if iOS can do it as well(though I do know it has multiple input detection). In the very least, I highly doubt Graal has the ability to interpret such input.