Build a basic mobile app on tracking (geofencing )

A tracking app with simple UI which can :- 1) Track multiple users at a time 2) the main head user can specifies the area to be tracked and if the tracked user goes beyond the specified area, a notification of red alert zone should be popped. 3) if the phone is made off of the tracked user then the head user should get a notification of how the phone was being off such as due to battery low, or made switch off, etc. A tracking app which can 1) track the other users which will be connected to head /main user. 2) It should give notification if the person who is been tracked goes beyond the marked area. Features:- Add multiple users Geo-fencing Notification pop ups