Neil Batchelor

EncodeDotHost

A simple plugin to separate categories from products within the WooCommerce archive loop. 
By default the categories will be shown in a grid of 4 on desktop, three on tablet landscape, two on tablet portrait, and one on mobile. 
You can easily override this behaviour using CSS.

EDH Shop Categories

A simple plugin to separate categories from products within the WooCommerce archive loop.

Razorfrog Web Design

This plugin creates a widget to display and link to WooCommerce products by category in a dropdown menu. Visitors to your site will have one-click access to products in your sidebar (or other widgetized areas) without valuable real estate being used up by a regular products list.
Plugin options include the abilities to:
<ul>
<li>display all products or just products in a single category</li>
<li>sort by product name, price, total sales, number of reviews, date published, date last modified, or random</li>
<li>limit the number of products shown</li>
</ul>
This plugin is also compatible with the <a href="https://wordpress.org/plugins/post-types-order/" rel="ugc">Post Types Order</a> plugin, so you can also sort by your own customized menu order if desired.
With these options you can use this plugin for a variety of uses. You could use multiple instances of the widget to have product dropdowns for each of your categories; you could display the top 5 most frequently bought products in a specific category; you could display the top 20 most reviewed products in your entire store or just in a specific category; and so on.
Note
For sites with a very large number of products, it is not recommended that you display all products in a single dropdown because it would be both heavy on server resources and also just be difficult to use.

Product Dropdown Widget for WooCommerce

Dropdown widget for WooCommerce products with category selection and sorting by price, reviews, or other criteria.

EDH Shop Categories vs Product Dropdown Widget for WooCommerce