Many people spend a lots of times for sitting still while working on their desks. It cause our muscle to get hard and sore. So I think it is good to have a friendly bracelet that notifies you to stand up and have a quick stretching time.
How it works:
Arduino will count (tilt sensor) the time and after an hour it will light up a LED. In order to reset the LED a user needs to do a exercise (a ball of tilting sensor will bounce several times).