App for Balance Assessment on Mac

I'm looking for someone to code an app for me to assess posture using a Nintendo Wii Fit Balance Board. The program should plot the patient's center of gravity on a 4 quadrant window over a 10 second period. It should also calculate the average percentage of displacement right or left and anterior or posterior in 2 independent values. There is no need for the program to give actual weight.

There should be a "start" button and a "reset" button.

I'd love to hear ideas!

And how much will you pay?

I was thinking $100-200 but I'm not sure how much time something like this would take.