sepehri I can't find the users on my admin control dashboard. I want to be able to control and approve every sign up before any user have access to the forum content.
You can use user directory by FoF: 
#5682
In permissions you can control who can see discussions, make user groups (i.e. "Approved" or "Verified", after you get notification about new user you can review it and then assign desired role). I noticed that this practice automatically verifies user email/user account, so be careful...
