The wearable activity tracker is becoming a bit of a trend at the moment - First Nike, then Jawbone and now Fitbit, with the Fitbit Flex.

Designed to record your daily activity as well as pair up with the Fitbit smartphone app, the Flex is the value for money wristband of the activity tracker bunch.

The Fitbit Flex wristband is a stretchy piece of plastic - coming in various colours including red, black and green - into which the Fitbit fits. On top of the Fitbit are five dots which, like most activity trackers, show how many steps or progress you have made toward your goal.

These lights shine through a clear plastic part of the wristband. Take the Fitbit out to charge it. The device's accelerometer is used to activate the lights that show progress. All you need to do is tap it on the side.

The whole thing syncs with iOS over Bluetooth, giving it a bit of a leg up over the likes of the Jawbone Up. Android syncing is coming for the device.

The Fitbit app will show steps walked and distance travelled, as well as estimated calories burned. Sleep can also be tracked. This is then all synced to the Fitbit app over Bluetooth 4.0. It also integrates with MyFitnessPal for those who want to keep track of calories and what they have eaten.

The Fitbit Flex will be on sale in spring and cost $99.