Thanks for wanting to help! The best thing you can do is use the software, and if you find any bugs, report them or fix them.
Open an issue on github, https://github.com/jake-87/fortran-calc and provide as much info as possible.
Branches are labeled like this:
- Feature branch: add/whatever
- Bug branch: bug/whatever
- Critical bug: critical/whatever
Please adhere to this when making branches, but otherwise, feel free to help!