Display the pending comments count next to the approved comments count in the admin listing of posts.
NOTE: This plugin is deprecated as of WordPress 4.3, which now includes a display of the count of pending comments alongside the regular count of comments. And it does so in a more aesthetically pleasing fashion than this plugin ever did, so if you are using WP 4.3 or later, there's no need to use this plugin. In fact, it won't do anything for you if you try to use it. The plugin is still fully functional for WP 4.2 and earlier.
The pending comments count will appear next to post comment counts in: