I was just reminded of how useful this was for me, since i was too lazy to setup fan curves in the cli with pwmconfig. This took me 10 minutes of tinkering and my temps went down a lot under load on my gpu and the machine is a lot more silent when idling.
Since there is no screenshot in the repo i thought i'd drop this here. You technically don't even need to install the GUI app (but you can) since the daemon starts a webserver on localhost:11987 which looks like this:
Yup it immediately picked up my Nvidia GPU and let me handle it's temp curves and case - fans based on it like a charm.
Just uninstalled fancontrol-gui and gotta keep this one^^
I'm on a sff case and the GPU is often times the most hot thing in this so i need to control my case fans based on the Nvidia temp instead of CPU temp or something else.
What happens when the daemon is stopped depends on the implementation of your drivers. I have driver for my mainboard fans that is not in the mainline linux kernel but maintained by a single guy that just recently added the functionality to give back the control to the motherboard (bios settings).
Long story short: if you disable coolercontrol and notice that your fans don't change their speed when the temperature rises / falls, or act like they did from the bios settings, reboot your system.