xdark

Easy Related Posts is a WordPress plugin that displays posts related to the one a user is currently reading. 
Easy Related Posts can display related posts in main content area or in sidebars through a widget. 
Equipped with 3 eye catching fully responsive themes, supports basic modifications on them from admin panel. It also has a theme system that let you modify or write your own themes to match you personal needs. 
Through an intuitive algorithm it creates “relations” between posts and rates them based on posts categories and/or tags in a way so these ratings are as much as accurate they can be. 
Last but not least in any way, Easy Related Posts uses the best coding standards and practices with mind in security.
If you like this plugin please support the developers. You can do so using the links inside plugin settings page or by purchasing the PRO version.
PRO version can be purchased from <a href="http://erp.xdark.eu/downloads/easy-related-posts-pro/" rel="nofollow ugc">here</a>. 
To see a full list of features and compare them to the PRO version please visit <a href="http://erp.xdark.eu/version-comparison/" rel="nofollow ugc">this page</a>.
Easy Related Posts wont spam your visitors with content from other sites, ads or in any other way.
<a href="http://erp.xdark.eu/demo/" rel="nofollow ugc">See the demo</a>
This plugin requires PHP version 5.3 and above.
Features:
<ul>
<li>Easy to setup</li>
<li>Choose displayed content: excerpt length, thumbnail resizing and many more.</li>
<li>Choose if related posts should be fetched by categories or by tags</li>
<li>Exclude posts that have certain categories and/or tags from related posts</li>
<li>Prevent related posts from spawning in certain categories or tags</li>
<li>Display related posts as an eye-catching pop up block</li>
<li>Display related posts through a widget or/and in main content area</li>
<li>Options optimized before activation for most of the cases</li>
<li>Really fast, not a single database entry (I really love clean DB’s)</li>
<li>Responsive design</li>
</ul>
Please report any bugs or features you’d like to see in feature releases <a href="http://erp.xdark.eu/bugs/set_project.php?project_id=3" rel="nofollow ugc">here</a>

Easy Related Posts

Displays related posts in the end of each post or/and in sidebar through a widget

fransoft

Floating Related Posts adds a banner with a cool list of related content.
You can place Floating Related Posts at the top or bottom of your website and easily customize it with the help of the live preview. You can change background color, text color, buttons style, font size, and so on.
<h3>FEATURES</h3>
<ul>
<li>Boost your metrics: up to 20% increase of page views</li>
<li>Related by tags, categories or both</li>
<li>Filter by time range</li>
<li>Fully customizable: modify size, position, colors and style</li>
<li>Scroll trigger</li>
<li>Compatible with Google Analytics</li>
<li>Live preview: what you see is what you get</li>
<li>Easy translatable to your language: includes POT template</li>
</ul>

Floating Related Posts

Just install, customize and relate content easy and fast

Relate content fast and easy

Works great, easy to customize. And “The Algorithm” is even better. Great solution, thanks a lot!

Better than related posts solution in original theme

Increase your page views and bounce rate with Floating Related Posts

Easy Related Posts vs Floating Related Posts