This is the Vikinghammer Tweet plugin.
You can set it up to post tweets based on new posts or comments to your blog. This requires that you enter your Twitter credentials.

Vikinghammer Tweet

Send a tweet for any new post or comment to your blog.

Scott Taylor

Most ratings plugins contain too much code: inline JavaScript, messy markup, weird CSS. Rate is simple, hardly intrusive, and completely overridable.
A Post/Page/Custom Post Type’s rating is the average of all comment ratings. A user can leave a rating when commenting, and change that rating inline after leaving a comment (if logged-in or Cookie’d).
Don’t be afraid to play around and extend the code: drop a <code>rate.css</code> file in your theme directory and mine won’t even load (by default, Rate stars are transparent with a white border, so you can use <code>background-color</code> to set your stars’ colors)!
<pre><code><?php 
// in this version, you need to insert these functions into your theme for ratings to appear
// you don't have to use the_rating(), the comment_rating() will work by itself, but the_rating() will not

// for a Post, Page, or Custom Post Type (average of all comment ratings)
the_rating();

// for a comment
the_comment_rating();
?>
</code></pre>
Read More: http://scottctaylor.wordpress.com/2010/11/30/new-plugin-rate/

Rate

Most ratings plugins contain too much code: inline JavaScript, messy markup, weird CSS. Rate is simple, hardly intrusive, and completely overridable.

Vikinghammer Tweet vs Rate