水野史土

This plugin shows the list of the categories of your blog. When you click one of the categories, you will jump to post-new.php, where the category you clicked is selected.
Usually you go to post-new.php and write a post, then you select the category of the new post. This flow may result in publishing without selecting any category. In such cases, the post is categorized as ‘Uncategorized’ and you have to select a category after publishing.
This plugin solves this problem. You can select one category before writing a post, no more unwanted Uncategorized.
<a href="http://plugin.php-web.net/wp/category-select" rel="nofollow ugc">Japanese description</a> is also available.

Select Category to Post

Category names are shown on your dashboard with a hyperlink, and when you click one, you will go to post-new.php, with the category already selected.

Sergio

Removes category base from your category permalinks (optional). By default is enabled. 
Removes parents categories from your category permalinks (optional). 
Removes tag base from your tag permalinks (optional).
The three options above are optional and generate their own rewrite rules.
Compatible with WPML Plugin and WordPress Multisite.
Read the <a href="https://wordpress.org/plugins/wp-no-base-permalink/faq/" rel="ugc">FAQ</a> before use.

WP No Base Permalink

It solves the main issue with category permalinks. Simple and effective.

Does the job!

Removes category base or parents categories or tag base from your permalinks. Compatible with WPML Plugin and WordPress Multisite.

Select Category to Post vs WP No Base Permalink