My site is still under construction - I am still in a learning curve. So far this is one of my favorite plugins. I wanted a plug in where people could "choose their own group". I set this up, and then with Admin Editor Pro... I gave users the power to "choose their group". I activated "groups_access" for them. (Could have done the same using User Role Editor.) When you do this, all of the groups appear on their profile. They can "check a box" and pick their group. My groups are free... which is what this plug in is for. It's just a very simple great plug in. Your groups appear in your user page color coded.
But, I will change some permissions. Even though my site is free, there are different level page permissions. With this plug-in, people "place their orders". Then, with User Role Editor, you simply add the corresponding additional user role applicable for the group... making sure the people have qualified to go to that level and join that group (I have qualification requirements for some groups).
I want people to have that ID in their profile immediately upon requesting the group... then I go through and make the change for htem. I didn't want those heavy membership programs... and role scoper was the only program I found that let people request to join a group. And with that, it was more steps for people, and not the immediate gratification of checking the box,it's on their profile page, and they immediately show up in the member list page of that group (linked via shortcode)... like with this plugin.
None of the membership plugins I tried worked, really... they slowed down my oh so slow shared server site... but I really like this simple plug in. It hasn't slowed down my site... and it has done what I wanted. I love the colors. :)
**And "brief" is not my specialty (i.e be brief and descriptive). I like words. :)