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.

sydcode

This plugin allows for custom editing of product prices in WooCommerce. This version only supports simple and external/affiliate products, but support for variable products will be added to a future version.
This is not an official WooCommerce plugin. Please do not bother the nice WooThemes people with support questions. All questions and suggestions should be posted in the plugin forum.
Thanks to Anthony for sponsoring this plugin.

WooCommerce Prices

This plugin allows for custom editing of product prices in WooCommerce.

WooCommerce Auto Category Thumbnails vs WooCommerce Prices