Christian Schenk

If you’re a WordPress admin you probably want a plugin with the following features:
<ul>
<li>install, update and delete plugins and themes</li>
<li>it should be able to handle various locations, i.e. at least these <a href="https://codex.wordpress.org/Plugins#Plugin_Repositories" title="WordPress Codex Plugin Repositories" rel="nofollow ugc">plugin repositories</a> and maybe some from <a href="http://www.google.com/search?q=wordpress%20plugins" title="Google search on WordPress plugins" rel="nofollow ugc">somewhere</a> else.</li>
<li>basic search functionality for all these plugins and themes</li>
</ul>
This plugins lets you do (almost) all of these things.
Have a look at this <a href="http://www.youtube.com/watch?v=-BzX7bv3DgM" title="Introduction to Extension Manager for WordPress" rel="nofollow ugc">video</a> to see how it works.
<h3>Compatibility</h3>
This plugin was tested with PHP 5.2.x. Currently it won’t work with 
older versions, i.e. PHP 4. Please be patient until I’ve fixed that.
But it’s possible that this plugin will never work with PHP 4 because 
it’s likely that I will not find the time to implement that. So please 
consider updating your installation of PHP.
If you’d like to help me fixing compatibility issues write me an <a href="http://www.christianschenk.org/legal-notice/#contact" title="Contact me" rel="nofollow ugc">e-mail</a>.
<h3>Videos</h3>
Have a look at this <a href="http://www.christianschenk.org/projects/wordpress-extension-manager/video-for-this-plugin/" title="Introduction to Extension Manager for WordPress" rel="nofollow ugc">video</a> to see how it works.
<h3>Licence</h3>
This plugin is released under the GPL.
<h3>Translation</h3>
This plugin is available in these languages:
<ul>
<li>English</li>
<li>German (I’m working on it)</li>
</ul>
If you want to help me translating it into other languages <a href="http://www.christianschenk.org/legal-notice/#contact" title="Contact me" rel="nofollow ugc">drop me a line</a>.

Extension Manager

This plugin helps you to install, upgrade, delete and search for plugins and themes.

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.

Extension Manager vs WordPress Changelog