Rajesh

Automatically remove the bad and broken links from the view of human visitors and search engine robots.
<a href="https://downloads.wordpress.org/plugin/broken-links-remover.zip" rel="nofollow ugc">Download now!</a>
<a href="http://techblissonline.com/broken-links-remover/" rel="nofollow ugc">FAQ</a>
Some features:
<ul>
<li>Broken Links Remover removes(hides) bad/broken links from the requestor’s(search engine or human) view</li>
<li>Bad/broken links dashboard</li>
</ul>

Broken Links Remover

Automatically remove the bad and broken links from  the view of human visitors and search engine robots.

husani

Searches various data sources (Google Blog Search and Twitter) for posts related to your content and displays links/summaries on your page or 
inside your posts. These links and summaries can be displayed anywhere and any way you wish — below your post, in a sidebar, etc. With the 
magic animation power of jQuery, SMIRC content can be hidden until a user clicks the customizable header.
SMIRC performs related content searching (at least in this version) by creating RSS feed URLs for the various data sources. The RSS feed is 
parsed and converted into XHTML for display in your blog.
All PHP is separated into logical classes and files, and all XHTML is standards-compliant. Lists of links, authors, and summaries are built 
using standard UL and LI tags, and can be modified to fit your theme via two CSS files contained within this plugin.
SMIRC is released to the WordPress community under the GPL. Please feel free to modify as you see fit, and if you find this plugin useful, donate 
to the author. All feedback is welcome at wordpressplugins@husani.com, and you can visit the author’s websites at http://www.husani.com and 
http://www.evb.com.
UPDATE FOR v1.1: Fixed a bug with setting header text.

Social Media Integrated Related Content (SMIRC)

Like trackbacks, but not -- this plugin searches and displays content related to your CONTENT, not just posts that link to yours.

Broken Links Remover vs Social Media Integrated Related Content (SMIRC)