If you are used to link the ‘previous’ and ‘next’ posts on a wordpress blog using their own title, you have probably noticed how more often than not too long titles can cause broken lines, hence unpredictable results in terms of page layout.
The only workaround in wordpress so far was to replace the title of the posts with generic phrases like ‘next post’, ‘previous post’ and so on. With this plugin you can use the title of the post itself, and trim it as needed.
Features:
<ul>
<li>limits the length of the previous and next post titles to the number of characters you want</li>
<li>where necessary, truncates the title to the last space, adding three dots</li>
<li>shows the entire title of the post in the tooltip (mysteriously wordpress never considers the tooltips of the links)</li>
<li>sets the string that conditionally will appear before the link title, only if the link title itself is present (previously in wordpress you either had to add a string outside of the ‘next/previous post’ tag, thus causing it to appear in the page even if the link was not present, or you had to add the string inside the link generated by wordpress, with ugly results: for example if the string was just a simple dividing character like ‘|’)</li>
</ul>

Better Adjacent Post Links

Adds two enhanced commands to replace wordpress 'previous post' and 'next post' functions. Works with Wordpress 2.8+.

Pankaj Jha

Vietnam Indexing

<a href="http://onlinewebapplication.com/wordpress-seo-internal-links/" rel="nofollow ugc">Plugin Home Page</a> 

SEO Internal Links plugin provides automatic SEO benefits for your site in addition to custom keyword lists, nofollow and much more configurable options. SEO Internal Links can automatically link keywords and phrases in your posts and comments with corresponding posts, pages, categories and tags on your blog. In case the plugin finds more of once the same word in a post, it will only change the first one. This is to avoid black seo and inconveniences to the users. 
 
This plugin is no longer support by author “masdiblogs” so Vietdex Teams fixed it to work in PHP5.4 and php7. So many People still use this plugin, at least our team ! 
 
It’s a year from the last this plugin was updated, until it is updated again in the future, we need fix all problem in php5.4 and php7. So this plugin is modified by Vietdex team. It’s very important to replace old plugin with this plugin until author update his plugin.
<ul>
<li>Works on all modern browsers.</li>
<li>Work With all the cache plugins.</li>
<li>Simple configuration.</li>
<li>SEO Internal links allows you to set up your own keywords and set of matching URLs. </li>
<li>SEO Internal links allows you to set nofollow attribute and open links in new window.</li>
<li>Perfect solution to get your blog posts interlinked or add affiliate links to other sites.</li>
<li>Edit the options from the administration settings panel.</li>
<li>Custom keyword lists</li>
</ul>
<h4>Credits</h4>
<ul>
<li>Smart Links By <a href="https://profiles.wordpress.org/freediver/" rel="nofollow ugc">freediver</a></li>
<li>Modified and fixed all bug by <a href="https://vietdex.net" rel="nofollow ugc">Vietdex Teams</a></li>
</ul>

SEO Internal Links Revisited

SEO Internal Links plugin create internal links for your site automatically, base on keyword, tag, category, nofollow or many other features.

Better Adjacent Post Links vs SEO Internal Links Revisited