Invite Anyone
Makes BuddyPress's invitation features more powerful.
Tag Plugin: invitations
WP eCards
With this plugin you can customize your ecards and send via email and social media.
Invitations for Slack
Build a Slack community by allowing your visitors (or registered users) to invite themselves to…
WP Social Invites
WP Social Invites allows your visitors to invite their social friends on your website.
Protected Registration
A powerful Plugin to protect your Wordpress registration page.