I would like to create on VPN server, login panel, what will be working on mobile app as a login by gmail, facebook, email or guest, with updating simple information to SQL, like id of phone. Then I want to add searching for other user via this app, so the app will check is there another user already online, and give back info.
I know it is not casual question. But I am in sort of problem, and I need an advice. How long, how many hours, could take to experience programer, to create such a thing?