Adam Harley (Kawauso)

A quick adaptation of the theme restriction code for widgets. Can only restrict on a site-wide basis, though it will only affect those sites on which it’s activated. Does not restrict super admins. Plugins must be active on the main site to be controlled by this plugin (this is an issue with WordPress’ plugin structure).
See also: <a href="https://wordpress.org/extend/plugins/restrict-multisite-plugins/" rel="ugc">Restrict Multisite Plugins</a>

Restrict Multisite Widgets

Allows network admins to restrict which widgets are available on sites, similar to themes.

TrustedLogin

The easiest and safest way to restrict access to your WordPress site’s Dashboard and administrative menus. Remove Dashboard Access is a lightweight plugin that automatically redirects users who shouldn’t have access to the Dashboard to a custom URL of your choosing. Redirects can also be configured on a per-role/per-capability basis, allowing you to keep certain users out of the Dashboard, while retaining access for others.
<ul>
<li>Limit Dashboard access to user roles:
<ul>
<li>Admins only</li>
<li>Admins + editors</li>
<li>Admins, editors, and authors</li>
<li>or restrict by specific user capability</li>
</ul>
</li>
<li>Choose your own redirect URL</li>
<li>Optionally allow users to edit their profiles</li>
<li>Display a message on the login screen so users know why they’re being redirected</li>
</ul>
Blocking access to the Dashboard is a great way to prevent clients from breaking their sites, prevent users from seeing things they shouldn’t, and to keep your site’s backend more secure.
Allow only users with roles or capabilities:
You can restrict Dashboard access to Admins only, Editors or above, Authors or above, or by selecting a specific user capability.
Grant access to user profiles:
Optionally allow all users the ability to edit their profiles in the Dashboard. Users lacking the chosen capability won’t be able to access any other sections of the Dashboard.
Show a custom login message:
<ul>
<li>Supply a message to display on the login screen. Leaving this blank disables the message.</li>
</ul>

Remove Dashboard Access

This plugin is a must-have when working with public roles.

A must-have!

Disable Dashboard access for users of a specific role or capability. Disallowed users are redirected to a chosen URL. Get set up in seconds.

Restrict Multisite Widgets vs Remove Dashboard Access