[juliangoldsmith]

Oura could provide their app, but also make it possible to talk to the ring directly via Bluetooth. Not only would this solve the privacy issues, but it would make third-party apps more reliable (due to no more round-trip).

The amount of work Oura would need to do would be trivial: they'd need to provide a basic description of the format of the packets the ring sends over Bluetooth (or just release protocol headers/internal client libraries). They'd also need to not put in work to deliberately prevent other apps from connecting (which some manufacturers do; not sure about Oura).