Similar to FitBit, this is a device to lets you track your steps and encourage healthier habits. It's a band you wear around your wrist while awake and asleep. You can even wear it when showering. It works with the free accompanying iPhone app. When you sync it, the app shows how many steps you've taken and how well you slept (deep sleep, light sleep). The band vibrates to wake you up within 30 minutes of your scheduled alarm while you are in a light sleep. The part I like the best is the activity alert. I have the band scheduled to vibrate every 15 minutes during work hours to remind me to get up and walk around; otherwise, I could literally sit the entire workday in front of the computer. There's a food tracking option, but it doesn't really track anything. You take photos of your food and a few hours later, you'll get an alert on the app, asking how what you ate made you feel. Competitors have a better way to track. Jawbone has challenges and tries to encourage healthy competition among other users. So basically, this is used to encourage healthy habits. It's not the calorie counter some might be looking for, but I'm a big fan of the inactivity alert. Now why the 3 stars? You might want to wait on this product. I'm actually being very nice. I've had to return two of these bands. So, I like the theory, but with all the troubles, you may want to wait. Plus, if you want the band in any color but black, you have to wait anyway.