Garmin has a bunch of awesome activity trackers and wearables for adults. vívofit Jr. is an activity tracker designed just for kids that motivates them to stay on the move. It is durable and swim friendly. The device has over 1 year of battery life.
vívofit Jr not only tracks sleep, steps, and activity, it also comes with a parent-controlled mobile app. Parents can assign responsibilities and offer rewards for tasks. The watch has a sunlight-readable display. It has multiple band designs. Ships for $79.99.