> To implement its contact tracing functionality, Immuni leverages the Apple and Google Exposure Notification framework (see Apple’s documentation and Google’s documentation). This allows Immuni to overcome certain technical limitations, thus being more reliable than otherwise would be possible.
Ah my bad, thanks for the correction. I'm still at 13.4 and I haven't been overtly refusing upgrade notifications, so I thought it hadn't been released yet.
It up to countries and states to build apps on those APIs.