Yes, you can see that only on their profiles. But some users might post on your profile first and asked if they can add you, or let now you that they have added you, not all, but some do.
Or you can keep tabs on how many people have added you like I do but it definitely takes time XP.
Haven't seen anyone mention it in this thread, so here it goes...
There will actually be 2 different ways of connecting with another user in the new ArmorGames v3.0!
1) By becoming friends with that other user like the way one can on FaceBook with requesting and accepting, just like it is explained in the other posts;
2) By following another user, which will be the same version of a friends system just like ArmorGames (v2) has now. However, the followed user can see who's following him this time.
So there will be more than one option to connect with and keep track of other users on ArmoGames in the future! Smart development if you ask me! =)