mustansir

This plugin allows you to add a dashboard widget that manages specific taxonomies (Such as tags and categories or any custom taxonomy). Specifically the dashboard widget makes it easy to remove a post from a taxonomy of any kind.
Those who have themes, plugins, widgets that use the wordpress taxonomy system to place posts in various lists will find this plugin especially useful.
This plugin allows you to add a dashboard widget that manages taxonomies. It easy to remove a taxonomy term applied to a post.

Category Manager

The WP Category Manager plugin makes it easier to manage any taxonomy that is used to control the posts within widgets in the presentation layer

Mats Westholm

Add one or more Custom Taxonomy to your wordpress managed website.
This plugin is focused on an easy to use interface with small number of choices to make it easier to use for a non technical user.
MW Taxonomy let you choose
<ol>
<li>Taxonomy name in plural and singular,</li>
<li>slug</li>
<li>select the post types (default and custom) where your custom taxonomy can be used</li>
<li>select wheather it should be hierarchical or not</li>
<li>select wherher the taxonomy should be indexed by search engins or not</li>
</ol>
MW Taxonomy includes a widget Custom Taxonomy List for presenting taxonomies in the blog. You need to use a theme that supports widgets for this, that is a classic (non-block) theme. Use the plugin <a href="https://wordpress.org/plugins/classic-widgets/" rel="ugc">Classic Widgets</a> if you don’t find the widget.
Taxonomies can also be presented by Tag Cloud widget or menus (classic theme).
Works in multisite environment as well.
<h4>Docs & Support</h4>
Please ask support questions in the plugin [support forum].(https://wordpress.org/support/plugin/mw-taxonomy)

MW Taxonomy

Easy to use wordpress plugin to add a custom taxonomy

Category Manager vs MW Taxonomy