In the meantime, the phone will let you scroll by tilting it back and forward, which seems like it might be a nice upgrade over having to touch the scroll bar all the time.
The bottom-left 4 x 4 pads represent drum sounds (touch the slider to scroll up and down through even more sounds), while the bottom-right quarter of the grid serves as a clip-length control (press and hold the first pad, tap the fourth for a four-bar loop, etc.).