On some touch devices, content can often be out of reach or require a lot of physical movement to touch. Some touch devices enable a user to physically touch screen and drag finger in a scroll gesture movement. Other devices provide varying abilities to reach the content, including allowing a user to tilt screen in direction of intended scrolling, or watching a user's eye movements and scrolling screen accordingly. Some users may modify how they hold the device, but this makes dropping the device more likely. The user can also use two hands to interact with the device, but this can be inconvenient for the user. Some of these methods only work if an app/content supports scrolling.
USPTO Backgrounds
USPTO Backgrounds