Fitbit confirms it has begun the rollout of blood oxygen monitoring feature to some of its wearables (Jon Fingas/Engadget)

Jon Fingas / Engadget:
Fitbit confirms it has begun the rollout of blood oxygen monitoring feature to some of its wearables  —  Fitbit's devices from recent years have blood oxygen monitoring (SpO2) hardware, but they haven't used it — until now.  Users on Reddit and elsewhere have noticed that their Versa …