I am in love with the KDE System Monitor widgets. They were, of all things, what truly cemented the Linux switch for me.

I used Aquasuite on Windows to control my watercooling, and it can set up a vast amount of widgets on your background for easy monitoring of temps and other values. It will not run on Linux.

The KDE widgets give me basically the same experience, although missing a few things. It’s enough that I’m happy with it, and I can check temperature and flow rates at a glance if something starts acting fucky.

Works fine, but I often have to go to the website to get the latest update. F-Droid takes a while to catch up.