Igor Benic

Multisite Featured Image changes the box of the featured image for all sites. It can be used also in a single instance of WordPress and not a MU installation.
This plugin changes the box in the way that the default pop-up is replaced with the classic Media Uploader where you can choose images. Images From URL do work.
For a greater Multisite experience you can combine this plugin with the <a href="https://wordpress.org/plugins/network-shared-media/" rel="ugc">Network Shared Media plugin</a> and have a complete Media Sharing site.
Read about it on this <a href="http://siderrz.com/wordpress-multisite-shared-featured-image/" rel="nofollow ugc">article</a>.
<h4>Features</h4>
<ul>
<li>Using WordPress Media Uploader to set Featured Image</li>
<li>You can set an image from URL</li>
<li>Images from URL will be downloaded into the WordPress Media and it can be used for anything else inside WordPress</li>
<li>Downloaded images are saved in every registered image size </li>
<li>You can set the Main site on which you will download the images in a MU installation</li>
</ul>

Multisite Featured Image

Multisite Featured Image changes the box of the featured image so that you can use the classic Media Uploader also with Network Shared Media.

Ewout

waltervos

Use this plugin to display the featured image for any post or page in your sidebar. If a featured image has been set. If no featured image has been set, the plugin tries to use the image of the parent post/page. Otherwise, no widget is displayed.

Featured Image Widget

This doesn't pull in any photos in the sidebar. The title shows up, but no images are shown. Bummers. Maybe this worked before, but it certainly doesn't now. I am using Twenty Fourteen for the theme.



Doesn't work with latest WordPress

Provides a widget that displays the featured image for a post or page. If a featured image has been set. If no featured image has been set, the plugin …

Multisite Featured Image vs Featured Image Widget