A system may include electronic devices that communicate wirelessly. When positioned so that a pair of devices overlap or are near to one another, the devices may operate in a linked mode. During linked operations, devices may communicate wirelessly while input gathering and content displaying operations are shared among the devices. One or both of a pair of devices may have sensors. An orientation sensor, motion sensor, optical sensor, and/or other sensors may be used in identifying conditions in which to enter the linked mode and to identify a region where displays in the pair of devices overlap.