The first parent to register account with Ojoy watch app and bind the watch through scanning QR code on the watch screen will be the admin. 

One watch can be only bind with one admin. 

The admin can add other parent in the Ojoy watch App, Function - Address Book, and add as Family Member. 

The admin may also the option add other members in the family as Family member or friends. 

The difference between Family Member and Friend is that Friends cannot register App and check child's location and send messages through the App, they can only make and receive phone calls with the watch, but Family Member can login to App and check child's location, and also send/receive messages with the watch.