A Whoop band for tracking vulnerable relatives? Fitbit founders launch new screenless wearable with GPS, heart monitoring, sleep tracking and more — and even aspeaker so you can check in

Fitbit founders are launching the screenless Luffu Link, a new fitness tracker that has built-in GPS, LTE, and voice logging.

Fitbit founders are launching the screenless Luffu Link, a new fitness tracker that has built-in GPS, LTE, and voice logging.