Frank P. Walentynowicz

Setting featured images for posts / pages could be very time 
consuming, especially when your media library holds hundreds of 
pictures. Very often we select the same thumbnail for posts in 
particular category. This plugin automates the process by inserting a 
thumbnail based on category / thumbnail mapping while post / page is 
being created or updated. Now bundled with FPW Post Thumbnails.

FPW Category Thumbnails

Assigns a thumbnail based on categoryid/thumbnail mapping to a post / page when the post is created or updated. Built-in FPW Post Thumbnails.

Enrico Sorcinelli

Feature Image Extended extends featured image functionality allowing:
<ul>
<li>Hiding featured image in your themes for all post types.</li>
<li>Adding link to the featured image.</li>
<li>Adding thumbnail featured image in administration screens listing.</li>
<li>Featured image quick-editing.</li>
</ul>
<h3>Usage</h3>
Once the plugin is installed you can control settings in the following ways:
<ul>
<li>Programmatically by using <code>featured_image_extended_settings</code> filter (see below).</li>
<li>Using the Settings->Featured Image Extended administration screen.</li>
</ul>
If your theme uses a different call other than <code>the_post_thumbnail()</code>/<code>get_the_post_thumbnail()</code> in order to get the featured image, this plugin might not work. 
So, in order to get extended featured image settings and apply to your pages, you should use <code>featured_image_extended()</code> (see below).
<h3>API</h3>
<code>featured_image_extended( integer $post_id = null )</code>
It returns an array containing featured image extended information of <code>$post_id</code> post (or current post if you don’t supply an argument) like following:
<pre><code>array(
 'show' => true,
 'url' => 'https://myurl.com',
 'target' => '_blank',
 'title' => 'Image title',
)
</code></pre>
<h4>Hooks</h4>
<code>featured_image_extended_settings</code>
Filter plugin settings values.
<pre><code>apply_filters( 'featured_image_extended_settings', array $settings )
</code></pre>
<code>featured_image_extended_admin_settings</code>
Filter allowing to display or not the plugin settings page in the administration.
<pre><code>apply_filters( 'featured_image_extended_admin_settings', boolean $display )
</code></pre>

Featured Image Extended

Feature Image Extended extends featured image builtin functionality.

FPW Category Thumbnails vs Featured Image Extended