Like the original, Ace 2 tracks activity and sleep and comes with step challenges, encouraging one hour of activity per day. You can also set bedtime reminders, alarms, timers and call alerts. The new version looks a bit more durable, with chunky wristbands in watermelon and night sky. It claims to be swim-proof, and thanks to a ratcheting strap, your kid shouldn't outgrow it too fast. It also boasts up to five days of battery life.

Kids can access a Kid View in the Fitbit mobile app to see their activity, and Fitbit has said previously that it will never include calories burned or body fat percentages on children's devices. Through the app's Parent View, guardians can monitor activity, manage their child's account and approve friend requests.

Ace 2 isn't the only kid-focussed fitness tracker on the market -- Garmin also has a version. And while some might question why kids need fitness trackers, proponents hope they might help lower childhood obesity and diabetes rates. Plus, some parents appreciate that their children can get alerts and notifications throughout the day, when their phones should, theoretically, be silent.