Native Android app using the Apple/Google exposure notification API. The CWA development ends on May 31, 2023. You still can warn other users until April 30, 2023. More information:
CWA app has requirement of Android 6 and Bluetooth Low Energy, but that alone is not enough to get the full functionality.
To send the "Exposure Notification" beacon your device not only needs BLE but also a special feature called "Peripheral mode". That way you can never warn others if you are infected, cause your device never sends IDs to other phones. But you can get warned, cause your device is able the record others phones IDs.
Even with lack of that "Peripheral mode" on your device the CWA seems to work flawlessly from user standpoint cause neither google play service nor CWA shows the limitation that it is only working one way.
CWA app has requirement of Android 6 and Bluetooth Low Energy, but that alone is not enough to get the full functionality. To send the "Exposure Notification" beacon your device not only needs BLE but also a special feature called "Peripheral mode". That way you can never warn others if you are infected, cause your device never sends IDs to other phones. But you can get warned, cause your device is able the record others phones IDs. Even with lack of that "Peripheral mode" on your device the CWA seems to work flawlessly from user standpoint cause neither google play service nor CWA shows the limitation that it is only working one way.
Users can test their devices with this app https://play.google.com/store/apps/details?id=no.nordicsemi.android.mcp
@JProof provided screenshots here https://github.com/corona-warn-app/cwa-app-android/issues/674#issuecomment-646949156 Selecting device information and look for Peripheral mode supported - NO
Samsung A7 (SM-A700F)
Internal Tracking ID: EXPOSUREAPP-1667