Can an iPhone be attached via Bluetooth to a PC and be used as a signature pad?

I work for a company that has technicians out in the field with a laptop and an iPhone. We have a business system that we purchased that has a module where after the tech finishs their work the customer is supposed to sign off on the work performed. The software company is telling me that I need to get an external signature pad which is bulky and an added expense. Why can't I attached the iPhone to the laptop via bluetooth and have them sign on the iPhone with a styus? Has anyone done this or know of an App that I can use?