... where you can either upload a photo angled 45 degrees down at your shaved head and/or draw on a 3D virtual head, your hairline, and then it gives a time series over your head/virtual head showing how long your hair would grow out at the average of 0.5 inches/month, without any haircuts, styling, nothing, just gravity?

It's one thing to know the theory of hair growth time & what styles require what length of hair, another to get a visual of the points in time you should be looking at the mirror to start working on various looks (and not looking during the time it still looks like crap growing back in).

This might help people getting "quarantine cuts", but in my case I'm considering putting down the razor to shoot for feminine hair. Seems like I'd need to hire a full-time wigger if I wanted to cheat & keep shaving, so I'd rather regrow my own & be self-sufficient as much as possible.