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.

tsaiid

Featured Image via URL is a plugin to generate the featured image of post from the image url specified. 
The image will be fetched back and saved into the Media Library with all supported sizes. 
If the featured image is already present, the plugin will do nothing.
This plugin is modified from Auto Post Thumbnail by adityamooley.
For more details, see http://tsai.it/project/wordpress-plugins/featured-image-via-url/

Featured Image via URL

Automatically generate the Featured Image from the specified image url in post.

Featured Image Extended vs Featured Image via URL