I didn't know what forum this best fit in, so it landed here...
This interior ballistics software appears to be a (semi) free alternative to Quickload. Its user interface is nice, and so far has predicted loads very close to the reloading manuals. After 1 month it insisted on updating, which I did. Gordon wants $1 per month to keep the project running. This seems reasonable - only thing is, it is completely unclear what version you will get - all the downloads are the latest beta versions. And it is unknown if the paid version will require updating every month. He would do well to explain these things.
https://grtools.de/doku.php