You need to consider : Whether you have to do the location tracking request once (and available later in settings of the app) or for each friend you add.
If its only once, its easy and you can add it as a check box while registering the app. Else each time you add a friend, there should be a check box or an alert to confirm location sharing.
yes sir i want to ask permission for whether i can track his/her location. This would be taken as setting privacy. If one do not want to disclose its position can deny the request else if yes i can start tracking and locating on map,
But the query is how will i send that request? wll i have to send message or somthng else?