The size of a smart watch limits the available interactive surface for the user. Most current smart watches use a combination of a touch screen and physical buttons. Unfortunately, a small touch screen's usability is limited when it can be easily occluded, such as by a finger. In this paper, we look at extending the interactive surface for a smart watch to the back of the hand. Our approach reduces screen occlusion by enabling off-device gestural interaction. We define a range of supported bimanual gestures and present a prototype device.
