Software

Here is list oft software used for designing all around OpenSimSpark.

KiCad https://www.kicad.org/

Geda http://geda-project.org/ http://pcb.geda-project.org/

LTSpice https://www.analog.com/en/design-center/design-tools-and-calculators/ltspice-simulator.html

https://en.wikipedia.org/wiki/Comparison_of_EDA_software

TinyCad https://www.tinycad.net/