Most advanced and the most popular module for PrestaShop to upload files. Well featured, both in frotn and back office. WIth this addon you can build awesome web2print website

Main features for customers
- upload files to products 
- upload files to cart
- upload files to order
- custom customer files upload (not related to products, orders etc.)
- possibility to download uploaded files
- possibility to define title and descriptions of uploaded files
- possibility to manage files

Main features for admin:
- download files uploaded by customers
- possibility to lock / unlock files (locked file cant be removed, edited by customer)

- possibility to define accepted filetypes (extensions like .pdf, .zip, .tar, .tif, .eps etc.)
- possibility to upload files for customers
- possilbilty to manage uploaded files
- possibility to enable upload for only for selected products

 

and much more, details on module page: addon to upload files.