What I did is run the GPS program and then put a transparent window on top of part of the GPS window. that way I can still get to my app and have full screen gps at the same time. I actually own a license to Centrafuse with nav., I just never use it.
I change the opacity of the window when I want to see it. I use CoPilot for nav and I just got a newer version and the window I built needs to be moved. I just thought of a clever way to do it.
My app is in VB but you can do the same thing in C#.
Let me know if you have any other questions.