Gioxx

The plugin provides the administrator with a convenient maintenance page, called E-mail User Cleaner, which will be navigable through the WordPress administrative interface. 
From the E-mail User Cleaner page you will be able to: 
 – generate and download a CSV file containing a complete list of registered users on the WordPress instance. 
 – Specify one or more e-mail addresses (one address per line), corresponding to registered users on the WordPress instance, to be deleted from the system. 
 – Identify duplicated users (based on criteria that checks first name, last name and e-mail address) and decide to select and delete them, also referring to the last login date to the WordPress installation.

E-mail User Cleaner

Delete users corresponding to the specified email addresses.

thaikolja

Thumbnails Cleaner helps you keep your WordPress installation tidy by removing and regenerating thumbnails.
You can control all functions through the plugins’ main page found under “Tools”. You can:
<ul>
<li>Analyze your uploads directory, giving you an overview how many original files and thumbnails there are.</li>
<li>Clean thumbnails which means deleting them while keeping the original files.</li>
<li>Restore thumbnails to start out with a clean uploads directory. This function requires the plugin <a href="https://wordpress.org/plugins/regenerate-thumbnails/" rel="ugc">Regenerate Thumbnails</a>.</li>
<li>Create backups of your uploads directory to keep your files safe in the unlikely event that there is a problem.</li>
<li>Restore backups in case you have lost a file that was not supposed to be deleted.</li>
</ul>
Please see the <a href="https://www.koljanolte.com/wordpress/plugins/thumbnail-cleaner/documentation/" rel="nofollow ugc">official website</a> for a full 
documentation.

Thumbnail Cleaner

Cleans up your WordPress installation by removing and regenerating thumbnails.

E-mail User Cleaner vs Thumbnail Cleaner