What @Den has done with the Go2Sleep ring is great, but a feature I think is really needed in SAA is the ability to combine an arbitrary wearable with and arbitrary pulse oximeter at least. For example, I use Android Wear as the sleep tracking sensor (tracking movements) because I find it much more convenient than having the phone in the bed. However, I also want to track o2 saturations. Currently this is possible with the SAA-endorsed oximeter from “Happy” Electronics aka StressLocator which I own. However, the design of that oximeter is not great. I purchased the Go2Sleep ring thinking I would be able to simply use that instead of the StressLocator, but it seems that is not possible even with the add-on by @Den.
I understand SAA may not have the resources to incorporate every new wearable natively, but there should at least be an API so we can integrate arbitrary oximeters into SAA like the Go2Sleep ring while still using the built-in wearables (such as Wear OS) for movement and/or HR tracking. As of now I have to choose between sleep movement and HR tracking (Wear OS) or HR and oxygen saturations (Go2Sleep with add-on).