quan_flo

This plugins allows administrators to rename wordpress usernames. 
The account owner is gets a notification email about the rename process.
Install, activate, and then go to the Users->Rename Usernames menu to rename user accounts.
More about me and my plugins
Since the year 1999 I do administration, customizing and programming for several forums, communities and social networks. In the year 2013 I switched from another PHP framework to WordPress. 
Because not all plugins I’d like to have exist already I wrote some own plugins and I think I’ll continue to do so.
If you have the scope at forums or social networks my other modules might also be interesting for you. <a href="https://wordpress.org/plugins/search.php?q=quan_flo" title="ifs-net / quan_flo WordPress Plugins" rel="ugc">Just take a look at my WordPress Profile to see all my Plugins.</a> Use them and if my work helps you to save time, earn money or just makes you happy feel free to donate – Thanks. The donation link can be found at the right sidebar next to this text.

Rename Users

This plugins allows administrators to rename wordpress usernames.

neoslab

Medias Toolbox allow you to sanitize and rename automatically media files during upload using severals predefined patterns. Furthermore Medias Toolbox offer you the option to compress your JPG and PNG image file to optimize your website and page loading time.
<h3>License</h3>
Good news, this plugin is free for everyone! Since it’s released under the GPL, you can use it free of charge on your personal or commercial site.

Medias ToolBox

Do what the title say

Medias Toolbox allow you to sanitize and rename automatically media files during upload.

Rename Users vs Medias ToolBox