Develop a PrestaShop Module

The objective of this project is to create a PrestaShop v1.5.* module to integrate the e-commerce platform with InvoiceXpress platform. For this task we need someone with experience in PrestaShop, PHP and integration with APIs. We are also looking for someone to work in other projects and have a long term relationship with us. The InvoiceXpress API is all in English and can be found on their website. [login to view URL] Main functions to be implemented: - When the costumer orders on PrestaShop an invoice must be created with all the costumer data, products, taxes and transportation fees on InvoiceXpress; - When an order is canceled on PrestaShop the invoice must be canceled aswell on InvoiceXpress; - When a product is created/edited/removed on PrestaShop it must be created/edited/removed on InvoiceXpress; - When you verify that a payment has been made trough the payment gateway the invoice status changes to paid and is emailed to the costumer; This module must work with the payment gateway modules from HiPay and CompraF?cil. All the code must be commented in a proper way.