To extend the default left-column categories representation with a vertical drop-down menu for the categories list, use the Flyout Categories Menu add-on.
To enable the add-on, follow the instructions from Instaling Add-ons from X-Cart App Store.
To configure the add-on, proceed to the settings page. It provides three options that you can enable/disable at your choice.
Show number of products in category: Enable if you need to show the number of products in a category next to the category name.
Wrap long category names: Enable if you need word wrapping for long category names.
Show category triangles: Enable if you need to display a tiny triangle next to the names of categories that include subcategories. Categories that do not contain subcategories will not be furnished with a triangle. Having this option activated can help your store visitors to navigate through your category tree better.