twodayslate

Widget to display your site’s most recent categories.
Current options:
<ul>
<li>Max number of categories to display</li>
<li>Title</li>
<li>Display date</li>
<li>Icon (if set by <a href="https://wordpress.org/plugins/simple-category-icons/" rel="ugc">Simple Cateogry Icon</a>)</li>
<li>Display post count</li>
</ul>
GitHub: https://github.com/twodayslate/Recent-Categories-Widget

Recent Categories

Show your site's most recently used categories!

ajberasategui

This plugin provides a Search Widget similar to the default WordPress one but with the abilty of adding category select 
lists to restrict the search query to only those categories.
Any comments, reviews, support questions are very much welcome!!!

AB Categories Search Widget

Insert a search form widget that allows visitors to add category filters to the search query.

Recent Categories vs AB Categories Search Widget