No time wasters; No canned responses; No adverting bid; Keep the bid at $30.
Multiple Category selection option is already avaiable in the product entry form, just copy that multiple category selection funcationality to
1. Manufacturer entry form
2. Attributes and group form
3. Supplier entry form
(applies to add/edit/delete of these).
Category table is the same that applies to products. Addon would be just 3 mapping tables, that can be copy/renamed from product to category mapping table for 1, 2, 3.
Must follow the Prestashop coding guideline. Top of your bid add 'I read the details carefully'. Ask question for any clarification.