Good add-on, but quite expensive for adding so few features in my opinion. I find it very strange that a system like this is not available in XF by default... But anyway, as for features I would really like to see a code generation option that would allow the possibility of inviting users without knowing their email (just send them a generated code). I would also like to see integration with custom user fields, as in asking for referrer upon registration and integrating this into the system. Ultimately it would be nice if it could replace this SMF plugin:
http://custom.simplemachines.org/mods/index.php?mod=2567
Thank you for the suggestions. Both are already added to our list of enhancements and will be implemented quite soon.
Thank you!