system
A chat on subreddit /r/pcmasterrace
human
The calculator button is super useful to me as a programmer, I actually find it annoying when I use a keyboard without one and have to type calculator in the search bar like some kind of savage.
gpt
Estimator.  Same deal - usually at the end of the day I have 40 or so instances of calculator that I get to watch close like old school solitaire.