There are dozens od ways to contribute to Weblate. We welcome any help, be it coding help, graphics design, documentation or sponsorship.
Weblate is being developed on GitHub <https://github.com/nijel/weblate>. You are welcome to fork the code and open pull requests. Patches in any other form are welcome as well. The code should follow PEP-8 coding guidelines.
We do write testsuite for our code, so please add testcases for any new functionality and verify that it works. You can see current test results on Travis <https://travis-ci.org/nijel/weblate> and coverage on Coveralls <https://coveralls.io/r/nijel/weblate>.