FitBit One Wireless Sleep and Activity Tracker. During the day, it tracks your steps, distance, calories burned, and stairs climbed, and it has a digital clock. Come nightfall, it measures your sleep cycle, helps you learn how to sleep better, and wakes you in the morning. Sync your stats to your phone or computer, and then gain insights to your health through graphs and charts (helps you set realistic goals). It has a sleep wrist band, or clip it to your pants/bra/whatever during the day.