Aaron Edwards

Plugin management for WordPress Multisite that supports the native plugins page and the WPMU DEV Pro Sites plugin! Used on thousands of multisite installs across the web. 
Previously known as WPMU Plugin Manager, it uses a backend options page to adjust plugin permissions for all the sites in your network.
<ul>
<li>Select what plugins sites have access to</li>
<li>Choose plugins to Auto-Activate for all new blogs</li>
<li>Mass activate/deactivate a plugin on all sites in your network (Very Handy!)</li>
<li>Assign special plugin access permissions for specific sites in your network</li>
<li>And as Super Admin, you can override all these to activate specific plugins on the sites you choose!</li>
<li>Removes the plugin meta row links (Version, Author, Plugin) and any update messages for blog admins</li>
</ul>
Also, if you use the excellent <a href="https://premium.wpmudev.org/project/pro-sites/" rel="nofollow ugc">Pro Sites plugin from WPMU DEV</a> you will be able to charge for access to certain plugins!
A free plugin by Aaron Edwards of <a href="http://uglyrobot.com/" rel="nofollow ugc">UglyRobot Web Development</a>.
<a href="https://github.com/uglyrobot/multisite-plugin-manager" rel="nofollow ugc">Contribute on GitHub</a>

Multisite Plugin Manager

I haven't had any issues with the functionality of the plugin, but the interface for granting plugin access to individual sites really needs improvement. Right now it's shoved under the "Settings" tab when editing an individual site, but when a site has a lot of options, this can make the page HUGE. The list of plugins should really be in its own "Plugins" tab, much like "Themes".

Plugin works well but interface needs improvement

This plugin helped me a lot when I had to reactivate one plugin on over 100 sites because accidentally I have activated it for the whole Network previously.

Good job!
Air.

Nice help for multisite

The essential plugin for every multisite install! Manage plugin access permissions across your entire multisite network.

Ipstenu (Mika Epstein)

We’ve all had this problem: a group of spammers from <code>mail.ru</code> are registering to your blog, but you want to keep registration open. How do you kill the spammers without bothering your clientele? While you could edit your theme’s <code>functions.php</code> and block the domain, once you get past a few bad eggs, you have to escalate.
Ban Hammer helps you do that by preventing unwanted users from registering.
On a single install of WordPress, instead of using its own database table, Ban Hammer pulls from your list of prohibited emails from the Disallowed Comment Keys feature, native to WordPress. Since emails never equal IP addresses, it simply skips over and ignores them.
On a network instance, there’s a network wide setting for banned emails and domains. This means you only have one place to update and maintain your blocked list. When a listed user attempts to register, they get a customizable message that they cannot register.
For advanced documentation, including how to use on WooCommerce, please visit <a href="https://github.com/Ipstenu/ban-hammer/wiki" rel="nofollow ugc">the Ban Hammer Wiki</a>.
<ul>
<li><a href="https://github.com/Ipstenu/ban-hammer/" rel="nofollow ugc">Development</a></li>
<li><a href="https://github.com/Ipstenu/ban-hammer/wiki" rel="nofollow ugc">Wiki</a></li>
<li><a href="https://ko-fi.com/A236CEN/" rel="nofollow ugc">Donate</a></li>
</ul>
<h4>Privacy Policy</h4>
This plugin does not track data outside of what WordPress already collects. It utilizes the submitted email address to validate the domain and compares it to the list of prohibited domains and emails. No additional data is processed.
<h4>Credits</h4>
Ban Hammer is a very weird fork of <a href="http://www.joeswebtools.com/wordpress-plugins/no-disposable-email/" rel="nofollow ugc">Philippe Paquet’s No Disposable Email plugin</a>. The original plugin was a straight forward .dat file that listed all the bad emails (generally ones like mailinator that are disposable) and while Ban Hammer doesn’t do that, this would not have been possible without that which was done before.
Many thanks are due to WP-Deadbolt, for making me think about SQL and TTC for StopForumSpam integration. MASSIVE credit to Travis Hamera for the StopForumSpam/cURL fix! And then props to Helen Hou-Sandí for not using curl at all. Protip? Use <a href="http://planetozh.com/blog/2009/08/how-to-make-http-requests-with-wordpress/" rel="nofollow ugc">WP_http</a> instead!

Ban Hammer

Prevent people from registering via your disallowed comment keys.

Multisite Plugin Manager vs Ban Hammer