in PHP, based on Bootstrap
1. New Project or start from previous project
2. paste Excel content. Each line contains, in general: [product ID, product title, product type, product available sizes, product price per size, misc data]
3. similar to mailchimp "match columns on import addresses by copy & paste", match columns
4. your php script should list the .jpg files in a folder on server. Files are named [login to view URL], [login to view URL], ...
Then, for each product in the pasted excel file, your screen should ask what pictures are linked to the product.
It should be in jQuery with "previous", "next" buttons to change product.
Pictures should be displayed as thumbnails, so please resize them dynamically with GD2 or something similar
5. on results screen, list: (and save for future use)
-link to download matched file (you'll have to generate an import file for: Shopify, Prestashop, Magento using their documentation)
Oops: forgot to say: you should duplicate pictures' folder and rename pictures files with a certain pattern