PostRank is an extension for Google Reader that provides an option to filter all uninteresting stuff out of your eyesight, and keeps you updated on posts and news items that matter the most. It does this by aggregating engagement activity (tweets, votes, comments, etc) from over twenty-four different social networks, and then ranking stories based on how much engagement each has received.
After installing the extension, you will be able to view each post’s rank right within the Google Reader interface. Post ranks are brought in real-time, so you can easily know which stories are popular and receiving the most user engagement.
PostRank also lets you apply custom filters to hide low engagement stories in any feed or folder. PostRank filters works similar to Reader’s “sort by magic” feature, but provides better results for even low ranking sites.
Additionally, you can even enable PostRank for Google search results, and sites like Reddit, Hacker News, and many others in the extension’s options pane.
PostRank is available only for Google Chrome and Safari.
Install PostRank: Chrome | Safari