Key Codes 4+

I just discovered these folks as a company and they are both good and serious (no junk, but sometimes a little fun tossed in). I am trying their apps now (an option if you go to their website) and their apps are great (so far). Just discovered they are also on the App Store, so I came here to write a review.

They only need to improve the abiltiy to understand all the features of their apps. Every app should have a modest but decent manual, perhaps along with some good brief videos, that explain (not just show) what the apps can do. FAQs are not a substitute for a manual.

This helped me discover that when macOS system preferences remap a modifier key to Option, it actually remaps to Right-Option, not Left-Option.

This resolved some frustrating behavior when using Parallels, as for some reason Alt Tab was misbehaving... it's because Apple had me unwittingly sending Right-Alt Tab, which changes the behavior of the task switcher. I just had to add a registry hack to remap Right-Alt as Left-Alt to make Windows work properly again.

I'd still be pulling my hair out and trying to figure out what was wrong if not for this free tool. Thank you so much!

How does this not have a rating? Works exactly as described, no extra noise.
Helped me to diagnose a stuck key. I think this will also be really helpful understanding Dvorak <-> QWERTY mapping and my (overly-complex) programmable Moonlander keyboard.
App doesn't log any keystrokes when the window is not in focus. ... I like this point.