Activity monitors have been gaining in popularity, especially the FitBit and the Jawbone UP. According toWired, the new Shine tracker, which is now on sale in the Apple store for $120, has one feature that makes it stand out from the rest. It is designed to blend in with other nonathletic accessories, and it can be worn in a variety of ways: as a necklace, a bracelet, or a watch, or clipped to a piece of clothing.