I kick around app development from time to time and creating a feeds and speeds app seems pretty easy.
Thinking of a home page where one enters in the specific materials, bit sizes, router, etc, etc and it gives some recommendations.
I just need data to work with. That front end/design aspect is easy.
Ask 10 different users here and you’ll get 16 different answers for poplar.
I’ve been trying to work this sort of thing out for a while now — list of calculators at: https://www.shapeoko.com/wiki/index.php/Materials#Feed_and_Speed_Calculators
Once I finish up my work on a CNC box/finger joint box I’ll hopefully get back to that.