This new smart watch and activity tracker from Cactus Watches is perfectly sized for young kids.
Your kids will love the vibration alerts that remind them to move (how healthy is that!) or the alerts for incoming calls and texts. They won't want to take it off, and that's good because it also monitors your sleep. So it's a perfect girls and boys watch or gift.

Tracker Mini - Smart Watch Features:
24 HR dynamic heart rate monitor
step pedometer
track you distance
sleep monitoring
Call alert, caller name / caller ID
SMS notification alert
Alarm alert
Sedentary alert
Time and date
Camera and selfie remote control
Find my phone - anti-lost feature