scribu

AppThemes

With the current WordPress administration area, the only way to add existing users to a certain blog is by entering their usernames, one by one. It’s very time consuming.
With this plugin, you can do it in bulk, by using the familiar “Change role to…” dropdown:
<ol>
<li>Go to WP Admin -> Users.</li>
<li>Click the “Entire Network” link.</li>
<li>Check the users you want to add.</li>
<li>Choose the new role from the dropdown.</li>
<li>Press “Change”.</li>
</ol>
Note that you have to be a super-admin to be able to do this.

User Management Tools

Allows super-admins to quickly add users to a particular blog in a multisite installation.

Joe Cartonia

James Rosado

Brad Markle

Rafael Ramos

timph

InMotion Hosting

Manage all your WordPress websites in a single dashboard. Central 
allows you to manage themes, plugins & backups all from within a single interface. 
Using our single sign in feature, you can log into central and access any of your connected websites.

Central Connect

Connects users and sites with InMotion Central.

User Management Tools vs Central Connect