Is it a bracelet or a useful device? Or both things together? Fitbit Flex is an accessory designed for those who practice sports and always want to keep their daily activities monitored. It slips onto your wrist and via a free iPhone app you can count the number of steps, the distance traveled and the calories burned during sporting activity. It is made of silicone, lightweight, and can also be worn at the seaside, in the pool or in the shower: it is completely waterproof. It has a small row of five white LEDs that show the progress of tasks. But it also works when stationary and can be worn at night to monitor the duration and quality of sleep.
