Eric Binnion

cranewest

Allows admins to deactivate a user as opposed to deleting a user. Works with web and XML-RPC based authentication.
Once installed and activated, a checkbox appears on the user profile settings page. When checked, the user will not be able to login with the account. If they attempt to login, <code>This user has been deactivated. Please contact the administrator.</code> will be displayed in the login error box.

Deactivate WordPress Users

Allows admins to deactivate a user as opposed to deleting a user. Works with web and XML-RPC based authentication.

Andrew Skochelias

Pavlo Kotula

WordPress changelog – logs any uploads, updates, installations/uninstallations, activations/deactivations of themes, plugins and WordPress core. 
It could be helpful to easily find out the moment when something went wrong with your site and quickly fix the issue.
The plugin logs such actions: 
* Theme installation 
* Theme update 
* Theme activation 
* Theme deactivation 
* Theme removal 
* Plugin installation 
* Plugin update 
* Plugin activation 
* Plugin deactivation 
* Plugin removal 
* Translation update 
* WordPress update 
* WordPress reinstall

WordPress Changelog

It is a very handy plugin in a case when there a lot of people are working on the project. So you can track when and what was updated or installed. And with help of this plugin, you can quickly find out what caused any issues.

Useful plugin

WordPress changelog - logs any uploads, updates, installations/uninstallations, activations/deactivations of themes, plugins and WordPress core.

Deactivate WordPress Users vs WordPress Changelog