Tis plugin by Jose Llinares helps your users at the same time you improve your SEO.
Make your users find the interesting content in your blog by showing what the peoples is searching in your blog.
Improve at the same time the indexability of your site giving to Search Engines the words the users are demanding in your site and increase your rankings and number of pages indexed.
To make this plugin work you will need first to install Search Meter plugin.
Plugin homepage: http://www.josellinares.com/wordpress-plugins/