QuizUp’s platform is based on follower/ following model, where users follow friends and their activities. Tap a username/profile picture to navigate to their profile where you can follow the user.
What a about private profiles?
If you´re a private player, users can´t follow you unless you accept their follower request.
What do the icons on your follower/following list mean?
White icon: This user is following you.
Red icon: This user is following you and you´re following him back.
Note: if you accept follower request for a mistake it's not possible to make this user unfollow you. The best way for you is to block this person and the user can’t contact you, challenge you nor send you chat messages.