It’s not exactly the belle of the ball, and its name is in serious need of some marketing help; but the LifeTrak Move C300 activity tracker makes up for its lack of charm with some powerful bonus features, like waterproofness (to 90 feet!) and the ability to also measure heart rate.
On top of all that, the device’s energy requirements are so low that its coin-sized, non-rechargeable battery will last a year.