Desktop document Scanner GUI Linux

I have a cheap ebay overhead desktop scanner. I had a custom app/GUI built to drive the scanner written (in C#) by a freelancer here that does everything I want it to do - in Windows - and it works great. Im very happy with his work but he hasnt been here for some time so I cant find him to do this next part of the project. So I put this over to bidding. What I have Attached pic of the scanner. Very basic but suitable for my task. Attached pics of what Windows does when I plug it in - its basic plug and play, webcam 2.0. Attached photo of what the GUI looks like on the Windows desktop. It really is that simple. The GUI/app i had built basically does the following on my Windows laptop (with the scanner plugged in via USB). Open the desktop icon Push scan button (document with QR code scans) QR code on document identifies document details. That document is saved in the C drive in the folder designated by the QR code. I have all the source code for the C# Windows version that I can send to the successful bidder. Im not going to be sending code for anyone just to have a look at. What I want Im going to run the scanner via a Raspberry Pi - so i need the whole thing written in Linux. Im told that C# is a language that also works in Linux with some modifications. If you can simply 'convert' the Windows C# to Linux C# id be happy with that. The output (the scanned image) will need to save automatically on a USB or HDD attached to the R-Pi The program needs to be supplied so that when it installs it places a desktop icon to make it operate. The scanning GUI/app is 1 of 3 parts to a suite i had built for this scanner. The scanner part cost me $100 AUD and i can easily evidence that from this freelancer site. The freelancer built it for me in realt time as we chatted in the freelancer messenger system. It took him less than 3 hours and again I can prove that from this freelancer site. I am prepared to pay about the same price for this scanner GUI/app in Linux and expect it will only take you a day to do. Happy to answer your questions.