Features:

• Allows for the administrator to approve/delete new groups on the site.
• Allows update the "River Dashboard" with created groups.
• Allows you  to browse "groups waiting to be activated" and "activated groups".
• Provides a page that allows you to customize the email templates that get sent to users/admin for your site. Provides some built in macros to be used inside of the emails.
• Allows you to delete or make feature/unfeature "groups activated".
• Notify user when a group is created, activated or desactivated . 
• Notify admin when a group is created.
• Allows change username (admin) to notify of new groups in the activation queue.
• Allows change "the notify time" (hourly, daily, weekly, monthly) to notify of new groups in the activation queue.
• The group is visible only for admins and it's creator after a group creation. Only after the admin approve the group is visible for everyone.

Installation:

 copy groupaccess/ folder inside your mod directory. Goto -> Administration -> Tool Administration -> groupaccess -> enable

If you like this plugin recommend it, thanks.