We accept GitHub pull requests. Please refer to https://threema.ch/open-source/contributions for more information on how to contribute.
To report bugs and request new features, please contact the Threema support team through threema.ch/support.
We manage our app translations on Crowdin. If you’re interested in
improving translations, or if you would like to translate Threema to a new
language, please contact us at support at threema dot ch.