For me, it was perhaps simple-scan, a very simple and efficient GUI to scan documents. I used it with my Brother printer / scanner and it works like a charm. Especially since I do not scan stuff often, so a program with more complex UI would have the effect that I forget how to use it until the next time.
Kicad is up there with the paid options for electronic schematic drafting / PCB design. I don’t use a lot of KDE stuff since I also don’t use KDE, but Kicad is absolutely essential for me.
Despite the K in its name, KiCad is nothing to do with the KDE project. It’s an independent program started (iirc) at a French university. I agree it’s awesome, though.
Well now… TIL!