What's a good iOS app for monitoring stress levels and heart rate variability?

RelaxWatch: Stress&HRV Tracker is a solid option for monitoring your stress levels and heart rate variability (HRV) on your iPhone. It helps you understand how your body responds to stress by analyzing your heart's rhythm. The app uses your iPhone's camera to measure your heart rate and HRV, providing a convenient way to track your well-being without needing extra gadgets. It presents data in an easy-to-understand format, allowing you to see trends and patterns in your stress levels over time. RelaxWatch also offers features like guided breathing exercises to help you manage stress when you need it most. With a rating of 4.3, it's clear that users find value in its ability to provide accessible and insightful stress monitoring.