Urtak allows you to gather your users’ opinions by enabling them to ask and answer questions about your content.
Watu allows you to create exams with unlimited questions and answers, and define grades based on collected points.
Widgets in Columns allows you to show your widgets in desired columns and rows.
BuddyPress lets users register on your site and start creating profiles, posting messages, making connections, creating and interacting in groups and much more. It’s a social network in a box.
Viper’s Video Quicktags allows you to simply click one of the new buttons that this plugin adds to the write screen (rich editor included) and then paste the URL that the video is located at into the prompt box. You can fully configure how the videos are displayed and much more.