We accept GitHub pull requests. Please refer to https://threema.ch/open-source/contributions for more information on how to contribute.
Please note that pull requests will not be merged directly on GitHub. Instead, we apply the changes to our internal repository. Your contributions will then become part of the public repository once the next release is published.
To report bugs and request new features, please contact the Threema support team through threema.ch/support.
We manage our app translations through Crowdin. If you're interested in improving translations, or if you would like to translate Threema to a new language, please contact us through threema.ch/support.