A thumb extension that lets users master large-screen devices such as the iPhone 6 Plus and Samsung's Galaxy Note with just one hand. Most human thumbs are too short and stumpy to navigate large size smartphone screens. Japan-based Thanko came up with the solution of the thumb extender, which is a silicone-based device that slips over the user's real thumb. The life-like appendage extends the finger by an extra 0.6 inch (15 millimeters) of length. The stretched finger allows users to reach any spot on the big screen and a conductor at the tip ensures the screen registers its touch. The device is perfect for urban commuters clutching a briefcase or a subway strap on packed trains.