While this app doesn't require any special installation, it does use Shopify's own navigation system. Please set up menu items and collections then refresh the category list to see them as a nested category tree. We provide this screencast to make your journey through the process really easy.
Create your categories using menu items in the Shopify Navigation. For more information see the step-by-step screencast in the Help section above.
Refresh your category list using the 'Refresh' button in this admin interface, then check it out on your storefront.
[Optional] Set a top-level category to restrict the part of your menu structure that is displayed as categories. Or tweak the settings and refresh again to make it look just right for your store.