Misfit Shine Activity Tracker

Most activity trackers look like glorified snap bracelets, but the Misfit Shine – a waterproof metal disc that clasps to your clothes – is more sophisticated. It accurately tracks steps, distance, and calories, alerting you via a ring of tiny lights. Uploads are equally subtle: Tap it on your iPhone's screen and it syncs automatically. [$120; misfitwearables.com]