This chic smartwatch not only tracks steps, calories burned, distance travelled and sleep, but heart rate too. The ZeWatch4HR can be synced with the ZeFit app on any iOS, Android or Windows Phone device, letting users set daily goals, view their progress and analyse their performance. Heart rate statistics give wearers a glimpse into their overall fitness level, and what affects it. Users can make calls and payments through the watch, and use it to find their phones. It features a selection of watch faces and two choices of a strap.