Fitbit says its OS 5.0 has been developed exclusively for the new Versa 3 and Sense smartwatches, and older devices, including last year's Versa 2, won't get it (Ben Schoon/9to5Google)

Ben Schoon / 9to5Google:
Fitbit says its OS 5.0 has been developed exclusively for the new Versa 3 and Sense smartwatches, and older devices, including last year's Versa 2, won't get it  —  Fitbit Sense and Versa 3 start shipping today to customers, and as promised, they're arriving with a new software experience on board.