Working on it now. I originally thought it needed resolution as well as FOV for the calculations, but it turns out FOV is enough, you just have to set FOV after resolution change for it to work correctly.
Calculating this is no problem, however I need to make some changes to the calculator to support this. I'll see if I can get a quick beta version of this ready for BF4 within a week or so.
It's correct that the actual FOV changes depending on aspect ratio, but as far as sensitivity goes, resolution and AR doesn't affect it for CS:GO. So the configured FOV is what you should enter in the calculator
So in other words, the calculations are correct if you leave the FOV at the default 65? A lot of the CoD games are really weird when it comes to handling FOV
Do check again now, I found to cause of the problem. Different Android versions sends out different values in the http headers. This should be fixed now, drop me a line whn you have tested it