mogita

NOTE: ONLY works with multisite (aka WordPress Network) mode for now.
A super-easy-to-use Multisite WordPress news broadcasting tool for the Super Admin of the Network.
This plugin can be helpful for the Super Admins to push a notification, some kind of messages, even some Ads if they like, to every site admins who registered under your Multisite WordPress network. The added widget will go to the first place of all widgets, unless the site admins move it elsewhere.
This is a very simple task but yet no plugins ever met my simple need, so I made one for myself, and hope it helps you too.
Key Features:
<ul>
<li>Add a widget to every site admin’s dashboard (by Super Admin only)</li>
<li>Support HTML content</li>
<li>Comes at the top of all widgets</li>
<li>Site admins can move or hide it as they wish</li>
<li>Multi languages support (available in English and Chinese till now)</li>
</ul>
You can find the configuration page at Manage Network -> Settings -> Dashbaord Broadcast.

Multisite Dashboard Broadcast

Place a widget on top of every site's dashboard under the same Multisite installation, containing whatever content the Super Admin writes.

3dperuna

WPMU has great themes and plugins. Unfortunately, many, if not most, come with a nag notice that admins see about installing their notifications dashboard plugin. If you’ve bought one plugin for your site this is probably overkill. If you’re a developer you don’t need this on your client’s sites.
This is a simple plugin that removes the notice. The 1.3 version has been checked against WP 4.4 and recent WPMU plugins, but still should be backwards compatible with older versions of WPMU plugins.
Note: If you do decide to you install the WPMU notifications plugin, please deactivate this one first. Errors may occur if you don’t.
If you like this plugin consider donating: http://www.protospace.com/wpmu-no-nag-plugin/

Remove WPMU Dashboard Install Nag

Works as advertised. Now, why a plugin should be needed for this is another question altogether, and installing and activating this plugin is no substitute for filing an RFE to either add a close button to those annoying nags or a switch to turn them off (and their pref doesn't always work, apparently).
Thanks for this!



Simple and to the point

This plugin removes the nag notice at the top of WPMU plugins and themes.

Multisite Dashboard Broadcast vs Remove WPMU Dashboard Install Nag