Right now, we do not have dev docs for QloApps. So we suggest to every developer to take the help of Prestashop dev docs. If you know Prestashop then you will also be able to develop on QloApps.
But the payment gateways development will be a bit different. We made some small changes while managing the pricing in QloApps. So you will have to keep a check on that.
Now regarding the Prestashop Modules,
We have made changes in Prestashop codes to make it compatible with the hotel industry.
So the PrestaShop modules might not work in the QloApps. But if need some sort of functionality then please inform us we will suggest you the best possible way.