Michal Ozogan

This plugin fetch all tweets from Twitter, which has been written about some of your posts. For new article are changes cheching every hour. For oldone it is question one or two days.
You can set how many tweets to show and in swich format. It can be regular HTML or embed tweets generated by Twitter javascript.
List of tweets is automaticky show above comment form, but your can also do manually by put funciont <code><?php tmip_show_tweets() ?></code> into your WordPress theme.
Just remember, Twitter allow to search tweets only few days old, so i will show probably only in new articles. Be patient.

Twitter mentions in posts

Show tweets about your posts right under them.

Simpma

Increase engagement on your WordPress website by adding a Twitter-like mention feature to your comment section.
AtMention in Comments is a simple plugin that makes it possible for comment authors to get notified, whenever they are mentioned in a comment on any post.
<h3>Features of the plugin include:</h3>
<ul>
<li>Mention multiple comment authors in comment.</li>
<li>Mention both registered and non-registered comment authors.</li>
<li>Send notification email to mentioned comment authors. </li>
<li>Customize notification email sent to comment authors.</li>
<li>Customize @mention text color.</li>
<li>Notification email supports HTML.</li>
</ul>
<h3>How to Use</h3>
<ul>
<li>Simply type @ followed by the author name(@john), in a comment to mention the comment author.</li>
<li>Mention authors with spaces in their name by simply replacing the spaces with underscores. Eg: @joh__doe</li>
</ul>

AtMention in Comments

A plugin that enables you to mention @comment__author in comments.

Twitter mentions in posts vs AtMention in Comments