A blogger's best friend - Riddle makes it easy to quickly create and embed quizzes, lists and polls on your blog in as little as 60 seconds. “
Like Gate allows you to reveal some hidden/secret content when the user likes the article. Therefore increasing the likeness of your articles.
This is a "Share to Download" plugin, and works for Facebook, Google+ and Twitter.
Facebook Like Lock for WordPress. Locks your content and user can unlock by clicking on like button.
Share your viral Content and get traffic to your website.
Easily create and embed content that engages your community.