Dual-touch smartphone design concept
Ok, try picking up your phone and trying out the movement on the back of the phone that this would require. It doesn't work. If the majority of the phone is touch sensitive how are you supposed to hold it? It makes for really awkward movement of your hand and let's say you figured out how to get the scrolling down, you still have A HUGE issue of UI. The iOS experience nor its apps were made for any kind of cursor or mouse interface.If you need to reach across the screen without taking up screen real estate, use your other hand. Or use a stylus. Problem solved.Edit: Also not to mention that for the most part iOS does a pretty good job of letting me be pretty accurate with my bulky fingers. It's not perfect, but it's certainly not terrible.