This is a Magento 1.x module that I developed. My client has customers that sometimes need to purchase both the English and Spanish version of a product. So, we modified the Magento add to cart page to allow the customer to add two items to their cart at once. To my knowledge Magento doesn't have a way to add multiple items to the cart at once, therefore this was a bit challenging. You can see before and after screenshots below.

The stack for this is HTML, CSS, JavaScript, PHP and Magento 1.x. The project date is fall 2018.