The Oura is a fitness tracker, but unlike others it is a ring you wear on a single finger. See Wired article here and company website here. It seems to focus mostly on measuring your heart beat and temperature – all the time – and coming up with a variety of metrics and feedback for you based on that. The NBA and NASCAR have apparently given them to all their athletes (yes, I maintain that race car drivers are athletes, but we can continue the debate down at the corner bar when and if it reopens.)
I’m curious about fitness trackers, but if I ever invest in something I would like blood pressure and nutrition to somehow be incorporated.