The idea to include gain setting in SkyView/gmap originally came from @evangelyul. He thought of it, then referred to me for helping him with it. I tried to built on his idea with very limited knowledge of PHP and Bash script. Unexpectedly I succeded.
@evangelyul was actively involved in the entire development process. Please see this thread if you are interested in history of development:
https://discussions.flightaware.com/t/set-gain-from-browser/36278