How can I create a tracker app?

I wanted to create an app where the users would allow it to access their location, so with a login you would be able to look to the location of everyone who allowed it — a tracker type app

Nice. First step is to watch all tutorials from bubble…next step is to keep learning as much as needed to build it…some other things necessary is to learn about database structures and if going to have it open to the public user experience design and user interface design