Report what is wrong
A clear bug report, or a result that does not match your own test firings, is worth more than money. It is the only way some faults get found at all.
Support
Support development
The software is free and stays free. This page is for anyone who wants to put something toward the work behind it.
Ko-fi
One-off or monthly, whatever you think it is worth: ko-fi.com/rocketsalvo. Payments go through PayPal for now, with Apple Pay and Google Pay to follow.
Other ways that help as much
Tell me what is missing
Which propellant, which grain geometry, which export your club actually needs. Most of what is in RustPEP now came from somebody asking.
Say that you use it
Knowing the software is in real use, on real motors, is most of the reason it keeps getting worked on.
If Ko-fi does not work where you are, email [email protected] and we will sort something out.