Thinking of getting a Fitbit activity tracker? I got one! Here's my Fitbit Flex review including all of the Fitbit benefits and advantages as I see them, tips for using the Fitbit wristband, and how to use the Fitbit Flex tracker without a phone.Thinking of getting a Fitbit activity tracker? I got one! Here's my Fitbit Flex review including all of the Fitbit benefits and advantages as I see them, tips for using the Fitbit wristband, and how to use the Fitbit Flex tracker without a phone.