The Plugin add's a whitelist to your Server. Everybody who has the right permission will be able to join the Server.* You no longer need to add/remove every single user from the whitelist, do it automatically with your permission plugin
I was unable to find a Plugin just doing this, but it's very simple. It's very helpfull if you just want all your Team members to join your Server when your updating e.g., but don't want to be busy updating your default whitelist manually everytime there is a new moderator.