A new 3-axis joystick from researchers at Keio University could provide one of the least obtrusive tactile control experiences on smartphones that we've seen, DigInfo reports. Unlike other joysticks that take up a large portion of a handset's screen, this new device fits over a phone's front-facing camera. The joystick is elastic, and contains two layers of markers on the inside that can be detected by the camera — when the joystick is pressed the phone can see the markers skew or move position, allowing for a variety of inputs. It's based on "GelForce" technology that was developed earlier by the university's Tachi lab, with the original goal of developing a finger-shaped sensor for a robotic hand — but this new implementation could have a clear consumer appeal.