Wrist watches almost disappeared after the arrival of Smartphones, but the design and concept is still alive to harness additional benefits. How about a device that appears to be a wristwatch but actually charges your smartphone or other gadgets when they are out of juice?
A big problem with solar chargers is that whenever they pass through a shady region they get disconnected from the device and do not resume charging. One has to unplug the charging cable and then re-plug to restart the charging process. How irritating is that.