Make avaiable to your users for login with Devise or Facebook, and manage them and your admins. Each admin is related to roles with Rolify, and manages authorization with CanCan.

Creates little snippet like facebook or Google+ does from given uri.

Easy helper methods for adding custom social share buttons (Facebook, Twitter, Google+) to your Rails app.

Social linker generates share-links for the different social networks from a simple SocialLinker::Subject class. Supported networks are: Twitter, Facebook, LinkedIn, Google+, Pinterest, and email

StatsCollect is a little framework gathering statistics from external sources (social networks, web sites...), stored in pluggable backends. It can be very easily extended thanks to its plugins (currently include Facebook, Myspace, Youtube, Google).