Jan Štětina

Warning: This plugin is currently broken (at least for some sites) and I have no time to maintain it. I plan to solve all the issues from the support forum but I have no idea when that might happen (perhaps summer 2014). I am sorry and thank you for the understanding.
Provides a system for registration requests and their processing in multisite.
Blog administrator can place a shortcode <code>[murm-form]</code> on their blog, which will display a registration form. Visitors can then use this form to request registration. Such a request must be first moderated by the blog admin. If it is accepted, it’s passed on to the blog superadmin, who also has to approve it in order to pass. After approval the plugin creates given user accounts with subscriber rigths on the blog from which it was requested and sends login information to the user.
Per-blog settings
<ul>
<li>can be deactivated</li>
<li>notification via nag or e-mail on new requests</li>
<li>antispam (needs Akismet API key)</li>
<li>requests on the blog admin level can be automatically approved</li>
</ul>
Per-site settings
<ul>
<li>optional e-mail notifications</li>
<li>custom e-mail templates</li>
<li>blog administrators can be allowed to delete a request without notifying it’s author</li>
<li>requests on the network admin level can be automatically approved (this means that only blog administrators decide about their requests, if no error occures)</li>
</ul>
This plugin was developed for a small blog server (cca 30 blogs), so that superadmin would have control of newly created accounts (because some people were confused and got themselves unneccessary multiple user accounts).
Makes use of the <a href="https://wordpress.org/extend/plugins/wordpress-logging-service/" rel="ugc">WordPress Logging Service</a>.
In future there will be more options to modify default plugin behaviour.
<h3>Wishlist</h3>
Below are listed requests I know about and I’m going to process… eventually. Please be VERY patient.
<ul>
<li>“I have a request of asking for password on registration form. That way the user can pick out a password and have it automatically populated in the site user data.”</li>
<li>sidebar registration widget</li>
<li>attach custom admin message to user on request approval/denial</li>
<li>correct i18n, custom blog admin messages</li>
<li>custom shortcode css (error/ok) + information</li>
<li>save all settings as a single wp option</li>
<li>combine with pure-murm?</li>
<li>“I would like to add more fields like “country” in the Registration Page.”</li>
<li>custom new user default role</li>
<li>recaptcha on registration</li>
</ul>

Multisite User Registration Manager

Worked for me

Provides a system for registration requests and their processing in multisite. Two-level moderation.

albedo0

This plugin makes it easy to integrate an icon font built from the Icomoon site. Icons then easily integrate into your content via a shortcode

Multisite User Registration Manager vs Manager for Icomoon