Twice a week, I go to the office where I use my MacBook Pro (not the new one yet) and use peripherals provided by the company: a random HP mouse and a random HP keyboard.
The annoying part is that the HP mouse has a scroll wheel but no third-party software. This means that I have to change the scrolling direction in the macOS system preferences. It, however, messes with the natural scrolling of the trackpad. And I can't get used to old-school scrolling anymore.
Scroll Reverser fixes this. It reverses the direction of scrolling, with independent settings for trackpads and mice. That's all it does, and it's fantastic.
(Seriously, thank you, Markus!)