In Service Business there is a Document Called Completion Report/Delivery Challan/Job Order Report/Service Report - All Have one Function when job is completed you need to issue this document to get Signature from client on your App/Tablet/Phone - it is a Confirmation that job has been completed as proof - In UAE this Report is legal Report as Proof and in some cases presented in Court as proof.

Currently Companies are printing this as Booklets and get signature from Client - it is standard practice in every Company.

We need this to have in system and should be Created from Sales Order/Quotation and then from This Document you can convert into Invoice rest flow is same like your Software.

We can help your Development team in crafting this report as general which will apply in many business, attached is what we have currently using. It is a bit complex.

Regards,

Raheel