Smart ring or smartwatch? Which one would you pick? I love smartwatches, but this one is more convenient and comfortable to wear. Meet the @ultrahumanhq Ring Air. It's a small, light weight ring that pairs to Android smartphones and iPhone. It tracks your sleep, skin temperature, stress, steps, calories, and more. It can even tell you the best time to exercise, eat, and get some sun for vitamin D. Plus, it tracks the impact of caffeine on your body. The Ultrahuman Ring Air costs $349 and comes i