Konstantin Sokolov

Performs automatic keyword extraction. Adds a keyword taxonomy for browsing and a keyword extraction metabox in the post editing page. 
Available in English and Mandarin.

Eventflow Keyword Extraction

Automatic keyword extraction for SEO enhancement and improved user experience.

makong

Looking for the best internal linking plugin for WordPress? Look no further!
Everyone who involved in SEO knows about link building importance for getting higher rankings in Google, Bing or any other Search Engine. But really good SEOs know that internal linking is something you should not avoid. Look at Wikipedia website, their interlinking is something you need to be jealous about.
Why do you need internal links on your site? 
Because it helps you to give more contextual credits to the pages of your site, connecting them with relevant keywords.
Why to use Internal Links Generator for internal linking?
<ul>
<li>It is created by SEOs for SEOs</li>
<li>It has a few cool features you won’t find anywhere else</li>
<li>It has “noob” level easy setup</li>
<li>It works</li>
</ul>
What cool features Internal Links Generator has?
<ul>
<li>It counts how many times keywords from you list is found in your content (so you will what keywords from the list your content is lacking).</li>
<li>You can set the limit for keyword usage in your internal links (keyword priority setup, we all know that keywords are not equal).</li>
<li>You prepare everything in your beloved spreadsheets, then just import it! </li>
<li>You are able to find the keywords you want to link within the content of your website.</li>
<li>You can manually set how many words to look for before and after your keyword, which can help you find not only particular keywords but the surrounding words as well. That means that you can create a lot more variations of your anchor texts (remember: Google loves diversification in anchor texts).</li>
</ul>
So, are you ready to boost your internal WordPress SEO with Internal Links Generator? 
Don’t hesitate, hit download !
And don’t forget to leave your comments or ideas!  
We’ll gladly improve it for you!

Internal Links Generator

Looking at actual code of this plugin it's very clean.  No extra shortcodes or crap to slow down the site.  JS is compressed and css isn't too general to cludge up existing styles.
The UI is very straightforward and offers several ways to do what you want.  You define your own workflow and load keywords / target_urls however you prefer.
Works a helluva lot better than many of the other solutions without requiring a "pro" version.



Built well, simple ui and works

Simple way to automatically link a certain word or phrase in your post/page/custom content to a URL you specify.

Eventflow Keyword Extraction vs Internal Links Generator