This plugin is nothing more than a singe widget that displays your top posts in the sidebar.
It is based on <a href="https://wordpress.org/extend/plugins/stats/" rel="ugc">WordPress.com Stats</a>, so it does not include its own statistics system.
You need the above plugin for this to work!

WordPress.com Stats: Top Posts Widget

This plugin adds a sidebar widget, that is an excerpt of the 'Top Posts' section on the Wordpress Dashboard.

Tommie Hansen

Simple WordPress Plugin that gives you the ability to add a widget where the most popular posts for the current month is displayed. You also have the option to name the widget and define number of posts to show. Read more about it at: http://byme.se/wp-plugins/top-posts-this-month.html

WordPress.com Stats: Top Posts Widget vs Top Posts This Month