I am not sure how to design/approach "the login" functionality and I need your help in providing some guidance.
I want to provide a fb login functionality. I am just not sure about the username part. It is said by your website that we can use the facebook ID as a username. The problem that the fb id is something like 123456. So when you display the leaderboard to someone, all what they will see is a list of numbers rather than list of "names or display name"
So I am confused, what is the typical implementation for login provided that you want people to see meaningfull names of each other when showing leaderboard. What do you suggest?