We've tested our fair share of activity trackers and Polar is now adding one more to the fray. That's not a Nike+ FuelBand you see, it's the Polar Loop: a wearable for your wrist that keep tabs on activity, exercise and sleep patterns. Touting the "first waterproof" gadget of this sort, the company says the device can discern between activity levels and offer alerts and motivational feedback along the way. The Loop syncs to Apple smartphones via Bluetooth with its companion app, Polar Flow. Similar to Nike's wearable, Polar's offering displays goal info, calories burned, steps taken and the time on a LED display. If you're also after a heart rate monitor, the Loop can be combined with Polar's H6 or H7 hear rate sensors for that purpose when it arrives next month in black with a pink version set for release in 2014.