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.

Stefan M.

This plugin will set all Trackbacks and Pingbacks automatically to DoFollow Links.
The user comments will get after <code>X</code> comments from a unique mailaddress automatically DoFollow status. All other comments have NoFollow, except the Admin enable manually the DoFollow Status. The status which is set manual (if DoFollow or NoFollow) will overrides the automatical process. So, you have the control if someone gets sooner the DoFollow status, or never maybe. Of corse, the automatism can be disabled to do the hole work manually.
You get an support automatism, that you don’t need to check daily, but have the full control power.
Additonal this plugin validated all DoFollow URLs and will notice if there are broken links. Broken Links are very bad the Rank in the Search Engines (SEO).
Home Page of the Plugin: <a href="http://blog.murawski.ch/2010/09/wordpress-manual-dofollow-plugin/" title="IT Blögg - WordPress Manual DoFollow Plugin" rel="nofollow ugc">IT Blögg – WordPress Manual DoFollow Plugin</a>
If you have a wish for new functions, please contact me.

SMu Manual DoFollow

SMu DoFollow has many DoFollow Options (Manual or Automatism) and included URL Validator (Manual, WP-Cron or Cronjob).

wp-TrackbackPopup vs SMu Manual DoFollow