Shellbot

** 07/06/18 – Updated for the latest version of WooCommerce **
By default, WooCommerce displays a neutral and uninteresting category image placeholder in those cases where a category has 
no explicitly set thumbnail. This plugin simply replaces the placeholder image with a product image from that category.
User can choose whether to use a random product or the latest product from that category.
Feature requests welcome, please <a href="https://wordpress.org/support/plugin/woocommerce-auto-category-thumbnails" title="Plugin support forum" rel="ugc">post in the support forum</a>.
Usage
There is no complicated setup, simply install the plugin and configure WooCommerce to display categories. Any categories containing products but without a 
category thumbnail will now display a product image.
To switch between random and latest product display, see the settings page under WooCommerce > Settings > Auto Category Thumbnails.
More options coming soon. <a href="http://codebyshellbot.com/wordpress-plugins/woocommerce-auto-category-thumbnails/" title="WooCommerce Auto Category Thumbnails" rel="nofollow ugc">Plugin release page</a>.

WooCommerce Auto Category Thumbnails

Replace the default WooCommerce category image placeholder with a relevant project image instead.

isikom

Zauker

Plugin for WordPress woocommerce that allow add to cart sample item of a certain products
Compatibility with plugins:
<ul>
<li>WooCommerce Chained Products</li>
<li>Min/Max Quantities</li>
<li>Measurement Price Calculator</li>
</ul>
<h4>GET INVOLVED</h4>
Developers can checkout and contribute to the source code on the <a href="https://github.com/isikom/woocommerce-sample" rel="nofollow ugc">GitHub Repository</a>.

WooCommerce Auto Category Thumbnails vs WooCommerce Sample