The Evie Ring and App are designed to address the unique health needs of women at every stage of their lives. Through passively tracking and logging, the Evie solution shows: heart rate throughout the day; resting heart rate; heart rate variability; SpO2 (blood oxygen levels); respiration rate; skin temperature variability; menstrual tracking; activity profile (including steps, active minutes, and calories burned); sleep stages and duration; and mood/energy logging.