Matrix Powerwatch X £150 powerwatch.com
BARE NECESSITIES While Matrix calls it a smartwatch, it lacks apps and has a black-and-white screen. It does track your steps and calories burned – and uses body heat to recharge the battery, which sets it apart. EXPERT VERDICT Though using your body heat for power is unique, this is more of an activity tracker than a smartwatch, lacking a voice assistant and popular apps. It is more robust and hard-wearing than other watches, but the tech falls short, with steps often underestimated.