Fitbit has officially announced a fitness tracker for kids called the Fitbit Ace. 

The new tracker looks and acts like the Fitbit Alta, but in a smaller format for smaller wrists. It's really designed for kids aged 8 years and older, allowing them to track steps, activities and sleep. 

Fitbit's motivation is growing obesity rates in children - with the Fitbit Ace designed to look like the adult tracker so that children don't feel that they are being given something that's "babyish". 

• See Fitbit Versa here

Fitbit Ace will connect to a child's smartphone (if they have one) so they can monitor their own activity, but the focus is very much on being active, rather than losing weight: there's no talk of calories burnt or body fat percentages, but there is a rewards system for hitting activity targets. The guideline is 60 minutes of physical activity a day.

There will be number of different clock faces to customise your Ace as well as smartphone notifications.

Not only does the Fitbit Ace sync with a child's phone, but it can also play a larger family role. As a Fitbit user, you'll be able to track and message via the Fitbit app, so you'll have a wider picture of how active the family has been - you can also set family targets. 

There is no location tracking on kid's devices and it's fully compliant with COPPA guidelines, to ensure the privacy of children online.

It will come in two colours - blue or purple - and squares off against devices like the Garmin Vivofit Jr 2.

Pre-orders for the new Fitbit Ace are now open at £79.99 and it will be wider retail in Q2 2018.