There may be a new fitness monitor that is looking to take the top spot. The Reign Activity Tracker from Jaybird rules by providing more flexibility – not so much in letting you slack off in your workouts, but rather by featuring materials that shape to your wrist over time. There are eight interchangeable size options and this provides just enough customization. This activity monitor is compatible with Android, iOS and web apps and features wireless connectivity. It tracks your sleep and daily activities and helps you “reign” in your workout.