Cool, there is some work on a Libre CoronaWarnApp:
theScrabi/CoraLibre-androidNative Android app using the Apple/Google exposure notification API. - theScrabi/CoraLibre-android
theScrabi/CoraLibre-android-sdkCoraLibre-android-sdk fork of prestandard DP-3T to make compatible with the Google/Apple protocoll - theScrabi/CoraLibre-android-sdk