“…Wearables attached to a user's body as everyday objects, like a watch, a shirt, shoes, a bracelet, and so on, allow the user to be monitored and/or informed anytime, anywhere. Various such applications have been proposed for healthcare and fitness [11,32,45], social interaction [5,20,21,25], work support [37], safety awareness [1,15], education/training [8,36] and notification of messages. In particular, wrist-worn devices are very popular, boosted by the cultural affinity to watches and bracelets.…”