This Opencart free Ocmod module will show product availability on categories pages and in the featured module, bestseller module, lastest module and in the special module. By default when the product quantity is greater than zero, it will show Availability: In Stock, if product quantity is zero then it will show the product status assigned while entering the products.

Check demo at:
https://webocreation.com/nepalbuddha/desktops

More details at:
https://webocreation.com/blog/ocmod-module-to-show-product-availability-on-products-of-modules-page/