Is there a way to go back and check you phone and see any evidence that it had connected to a stingray or dirtbox? Or is it really untraceable from the user end??
Stand up. Sitting all day just isn't natural, no matter what. Learn to do your desk-work from a standing position, barefoot, no shoes, and with a lot of little movements and stretching from time to time. And the workout ideas already mentioned are also great - build up your core. This is the way.