Do I need to have the FFB Clip app actively on my screen in order for it to be working? Let's say that I load a new car/track combo and I have it on my screen and it's doing it's thing and then I pull up the app menu on the edge of the right-side of the screen and I click the FFB Clip App round button again to remove it from my screen. Is it still calculating and adjusting? And will it automatically start working the next time I hop onto another car/track combo?
As Ross Garland mentioned, as long as the app is enabled in the general settings in AC, you don't need to have it onscreen.
However, since there are currently a couple of bugs in the app (as I mentioned eariler), I recommend having the app open and keep an eye on the histogram.
If you see a tall and narrow spike appear in the histogram curve (can happen if you restart session or view the replay) it has been distorted and you should reset the histogram.
If the adjustment stops working ("FFB should be" and current gain value differ from each other), click the Auto/Manual button a couple of times until the button shows "Auto" and the adjustment starts working again.
The answer to the last questions depends on how you have setup the app.
If you have "PreferAutoMode=1" in the config file, the app will always be calculating and adjusting.
If you have "PreferAutoMode=0" in the config file, the app will only be calculating and adjusting the first time you run a particular combo. The next time it will not do any adjusting, instead it will use the calculated value from the first time you ran that particular combo.
This is unless you are forcing manual mode in the config, then it will never adjust.