kingjeffrey

From the authors of <a href="https://wordpress.org/extend/plugins/wp-typography/" rel="ugc">wp-Typography</a> comes wp-TrackbackPopup.
In WordPress the default trackback link behavior causes persistent user confusion. Knowledgeable users right-click on the link and copy the link location. But the vast majority of users click the link — expecting to copy the link from the browser’s location bar — only to be redirected back to the very page they were on. The standard implementation does not provide the expected result.
wp-​​TrackbackPopup resolves this issue. It uses unob­tru­sive JavaScript to create a popup win­dow when a user clicks the track­back link. The popup window pro­vides a text ver­sion of the track­back URL for easy copy­ing and pasting. 
The popup window may be styled to match your existing theme.
View the <a href="http://kingdesk.com/projects/wp-trackbackpopup/" title="wp-TrackbackPopup Homepage" rel="nofollow ugc">wp-TrackbackPopup homepage</a> for more information.

wp-TrackbackPopup

The standard WordPress trackback link behavior does not provide users their expected result. wp-TrackbackPopup resolves this issue.

mikegogulski

Pingcrawl aims to replicate WordPress.com’s “Possibly related posts” capability. It queries Google Blog Search for related blog posts (based on tags, or the post title if there are no tags), tries to verify that they are pingback/trackback compatible sites and, if so, adds links to such posts to the end of each blog post where it is invoked.
Scope-limiting configuration options are included to enable Pingcrawl to fit any WordPress installation’s memory/execution time budget.
<h3>Licence</h3>
Pingcrawl is free software released under the GPL. If you find it valuable, you’re invited to make a <a href="http://www.nostate.com/support-nostatecom/" title="Donate with PayPal, MoneyBookers, etc." rel="nofollow ugc">small donation</a> toward its ongoing support and maintenance.

Pingcrawl

Pingcrawl adds a "Possibly related posts" capability by querying Google Blog Search for post tags and pinging the results.

wp-TrackbackPopup vs Pingcrawl