Get the Fitbit Flex Wireless Wristband + a $20 Gift Card for $99 and free shipping at Target.com. Others are selling it for this price but not with the $20 card, which can be sent to your mobile phone, e-mail or through regular mail. That makes it a net price of $79, the lowest price we've seen for this popular fitness gadget. It tracks your activity during the day, including distance traveled, calories burned and active minutes, as well as your sleep patterns. It then matches this against personal goals. It can sync with either iPhones or Android phones and is available in black or in slate blue. Sales tax is charged in most states.