This application lets moderators add members to private topics in forums with the option Users can see topics posted by other users? disabled.
To manage the private users the moderator must have the option Can view all topics/questions? enabled for the forum.
Any moderator with the proper permissions can add/remove users in private topics.
Members added to a private topic can see it in activity streams, search, forum view, and notifications.
Each purchase entitles you to use the modification on a single Community installation.