While apps like WhatsApp already offer services to see the real-time location of your contacts, there are other specialized apps like FindNow that let you keep track of where your friends and family are.
All you need is the person's telephone number to send them a request from FindNow to follow their location. This way, if the person accepts, you can find them in real time on a map of the city. It should be noted, however, that you can only add friends or family with no limits if you have a premium account.
In any case, you can only see the location of members who have accepted your follow request. FindNow offers you the possibility to delete or block anyone who you don't want to follow anymore.
If you want to keep track of the location of a friend or family member, FindNow is a good option to have in mind.