Activate sleep mode on their Fitbit Flex or Fitbit Charge bracelet.
Fitbit Flex review: A most versatile, feature-packed tracker - CNET
Fitbit Flex Wireless Activity + Sleep Tracker Lime : Electronics
Fitbit flex - Sleep Mode - YouTube
Fitbit Flex- User Manual | Manualzz
Fitbit One vs Fitbit Flex 2 - Battle of the Cheap Fitbit Fitness Trackers | Review
Fitbit Flex Wireless Activity and Sleep Tracker Wristband - Slate - Newegg.com
Fitbit Flex Wireless Activity + Sleep Wristband, Slate, Small/Large : Electronics
Fitbit Flex review | TechRadar
Fitbit Flex User Manual - Manuals+
Solved: Huge Difference Between Normal & Sensitive Sleep S... - Fitbit Community
Giving up on Jawbone's UP
Fitbit announces the Flex wristband, a $100 fitness tracker to take on the Jawbone Up
Fitbit Flex Sleep mode demo - YouTube
Fitbit Technology | Sleep
How to Activate Sleep Tracking in Fitbit Flex - YouTube
Fitbit Technology | Sleep
How to Activate Sleep Tracking in Fitbit Flex - YouTube
Fitbit Flex 2 review: Tech Advisor
Fitbit Charge HR and Fitbit Flex Review
Fitbit Tips and Tricks: 8 ways to improve your Fitbit Flex usage
Fitbit Flex Wireless Activity + Sleep Wristband review - The Gadgeteer
Introducing Fitbit Flex 2, the Fitness Tracker that Fits Your Life - Fitbit Blog
Fitbit Flex Review - Activity Tracker World
