Spire Health Tag
Whether it's a watch, ring, or some other bauble, most fitness trackers work by asking you to wear something extra. The Spire Health Tag doesn't need you to wear anything than what you've already got on. These small tags adhere to the clothes you wear the most — think undies, shirts, or exercise gear — and use their built-in sensors to monitor all the things you'd expect, like heart rate, activity, stress levels, and sleep quality. They're washer and dryer safe, last around a year and a half, and come in packs of 1, 3, 8, or 15.