DjZoNe

Have you ever thought about, that putting a post in a category is so plain, and you need more sophisticated settings. Let’s say one post is more relevant to a category, than another one, so you want the more relevant posts to show up first, then the less relevant ones.
Now, it can be done easily, with Category Relevance plugin
<a href="https://downloads.wordpress.org/plugin/category-relevance.1.0.zip" rel="nofollow ugc">Download now!</a>
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Category Relevance

With this plugin, you can set a relevance value of a post against a category.

Marios Alexandrou

DigitalME

As the name suggests this plugin will completely remove the mandatory ‘Category Base’ from your category permalinks ( e.g. ‘mysite.com/category/my-category/’ to ‘mysite.com/my-category/’ ).
The plugin requires no setup or modifying core wordpress files and will not break any links. It will also take care of redirecting your old category links to the new ones.
<h4>Features</h4>
<ol>
<li>Better and logical permalinks like ‘mysite.com/my-category/’ and ‘mysite.com/my-category/my-post/’.</li>
<li>Simple plugin – barely adds any overhead.</li>
<li>Works out of the box – no setup needed.</li>
<li>No need to modify WordPress files.</li>
<li>Doesn’t require other plugins to work.</li>
<li>Compatible with sitemap plugins.</li>
<li>Compatible with WPML.</li>
<li>Works with multiple sub-categories.</li>
<li>Works with WordPress Multisite.</li>
<li>Redirects old category permalinks to the new ones (301 redirect, good for SEO).</li>
</ol>

No Category Base (WPML)

This plugin removes the mandatory 'Category Base' from your category permalinks. It's compatible with WPML.

Category Relevance vs No Category Base (WPML)