Dynamik.

With this app you can allow your members invite other members.

Features:
enable/disable system, select allowed groups to use this mod, three invite types: free -> user may or may not enter inviter name; force -> user must enter inviter name; invite only: user must be referred by invite form (with hashed keycode), list of all invited users, list of all invited users in ACP with filter options, invites by referral link, points system integration (any system!), promotion to the new group after reaching specific amount of referred users, ability to enable/disable member powers to raising people via ACP, info in member profiles about referrer, ability to add/edit/remove referred transactions, ability to turn off the "Referrer Information" block in profiles, ability to award referrer if his referrred member made topic/post, invite form, option to enable/disable custom invite message, option to disable invites from the same IP and much more, resend option to resend sent invites, option to approve transaction only if referrer add more than X defined posts. Note:
it's a first release of this app for a 4.x series. it's a lifetime purchase! Once time buy = lifetime updates (for a 4.x serie).