Keep track of every step, calorie and minute of sleep with the Striiv Fusion Lite Activity Tracker This slim activity tracker makes it easy to set and monitor personal fitness and sleep goals. It tracks steps, distance and calories during the day and monitors your sleep at night. It also provides call alerts when synced with your smartphone. Wireless syncing available with most computers, tablets, and iOS (iPhone) and Android devices. Plus, it's water-resistant, too.