While the Corona-Warn-App on Android is open source and free, it uses the Exposure API, which is provided by the Google Mobile Service (GSM). Hence, the Corona-Warn-App cannot be used on a Google-free android, e.g. LineageOS without Google Services. CoraLibre tries to reimplement the Exposure API and create a libre version of the Corona-Warn-App. There’s been significant progress reimplementing base functionality of the Exposure API using unit testing. The Corona-Warn-App hasn’t been adapted yet. It looks like, this will take some more time.