Fitbit is updating two of its most popular fitness trackers. The new waterproof Flex 2 and heart rate-tracking Charge 2 are available now up for preorder and will officially go on sale in the ...

We've tried Fitbit's mindfulness program, the Relax app, on all devices, and the EDA scan app on the Sense 2, which contributes to stress management numbers. We looked for ease of use, visuals ...