If you are opening a new issue or submitting a pull request, go for it! Don't be afraid that it's a dumb idea or a duplicate of another issue or an unwanted change or whatever. Maybe it is! We're still glad to have you! :^)
License. Gratipay is licensed under CC0, i.e., it's public domain.
More info. If you want to really get involved, then check out our full documentation for contributors: