Does it require the manufacturer's servers to be available to function?
I find it strange that in this whole, cool, nerdy review there's no mention of whether the device is fully yours and works on your phone, or if the app is (like in most smartwatches) just a glorified browser tab for your health data stored plaintext on a free service
Oh nice, I missed that bit, thank you! Saw the mention of Gadgetbridge but didn't know that meant it's usable offline. I've only ever used it for upgrading Pinetime firmware iirc
That makes this a seriously good option, I was looking for this a while ago but didn't find anything besides Pinetime, so I ordered a Pinetime and found out the heartbeat sensor is about as accurate on my wrist as tarot cards (I know it works for a few people, but most seemed to have the same issue). Everything else I could find back then was cloud-based or didn't do health tracking (or, n=1, didn't support Android)
I find it strange that in this whole, cool, nerdy review there's no mention of whether the device is fully yours and works on your phone, or if the app is (like in most smartwatches) just a glorified browser tab for your health data stored plaintext on a free service