Bill Erickson

When you upload an image, WordPress will automatically scale/crop it to many different sizes. If you’re not happy with the auto-crops, use this plugin to upload an alternative image.
If you have images showing up in your theme already, there’s nothing you need to do after activating this plugin. All WordPress functions that provide the thumbnail should now automatically work with your override image.
This plugin will add a metabox to every post type and allow you to modify every image size (built-in and custom ones added using add_image_size). You can use two filters to change these (image_override_post_types and image_override_sizes). For examples, see the documentation.
<a href="https://github.com/billerickson/Image-Override/wiki" rel="nofollow ugc">Documentation</a>
No support will be provided by the developer

Image Override

Allows you to override WordPress' auto generated thumbnails.

Nilambar Sharma

<h3>NS Featured Posts</h3>
This plugin adds checkboxes for each list item. You can easily check/uncheck the Featured flag. Checking the Featured will set the meta value yes for meta key _is_ns_featured_post. You can choose which post types you want Featured functionality from plugin settings.
<h4>Using in theme</h4>
This plugin only sets/unsets the meta key for assigned posts. You need to implement it in your theme to get Featured functionality.
Example:
<pre><code>$query = new WP_Query( array( 'meta_key' => '_is_ns_featured_post', 'meta_value' => 'yes' ) );
</code></pre>
This will fetch the list of posts that are checked as Featured.
Want to see how this can be used in a Page Template? 
<a href="https://gist.github.com/ernilambar/ad31b89b459e954fc950" rel="nofollow ugc">Click this link to see an example</a>

NS Featured Posts

A plugin for making posts, pages, or custom post types featured. Users can enable/disable Featured flags for selected post types.

Image Override vs NS Featured Posts