I plan my trips here. I use the charts, both sec and wac, a yardstick and a plotter, and pen and paper, as well as a simple calculator.
It takes me about an hour or so.
I have never used some computer program, both because I am not much good on computers, but also the planning and drawing the course line on the charts, just like I learned it in basic flight school 30 years ago, gives me an idea of what is really out there; not just some numbers on a computer sheet, that don't relate to much if I have to divert for weather or otherwise.