GUI app for system wide configuration

I can’t remember/find a GUI app that gave the user the possibility to change linux services and system features. Does anybody know its name?
It was an app with on-off sliders on the right side of the screen, and with that I had the possibility to control every aspect of my linux installation.
I seriously can’t remember its name as I’ve used it once.
It was something like “config”/“menuconfig”/“xconfig”/“kconfig” but more visually appealing by a graphical standpoint.
Any hint?

Basically, I’m searching for something like YAST.

It sounds like you might be talking about the gnome tweak tool:

Not at all, it was a dark themed app with a gui and vertical scroll for all the sections.
I remember red check boxes too.
Anyway, I tried the official menuconfig bundle and it doesn’t work on my system. It says that Kconfig is missing but that’s odd.
It’s not like I cannot install kconfig on my own but I didn’t expect the package to be faulty.
Anyway, the request for information is clear. I got messed up (memory wise) but not that bad actually…
I precisely said services. “Tweaks” does nothing with services and system wide configurations of drivers and kernel.
It was about the kernel too. It was like a qt GUI version of menuconfig.
Anyhow, thanks for the suggestion and for having spent some time reading what I said.