Comment Popularity free WordPress plugin

With this plugin, members of your site will be able to vote comments up or down. Think Reddit comments. After activating the plugin, there will be up/down arrows next to each comment and the total weight of the comment. Comments are sorted by weight in a descending order. Each commenter is allocated karma each time that one of their comments are upvoted. Admin users can give users the “expert” label which will attribute more weight to their comments. You’ll find an option under discussion for the default expert karma and it can also be changed on the user’s profile. Follow development of this plugin on Github Requires PHP 5.3.2 or newer.