StressEraser Pro is a handsome, simple, and sensitive device to measure heart rate variability (HRV) with your iPhone. On your iPhone screen, you can see your heart rhythm and how it affects your emotional system and how you can recharge your stress level. With this Heart Rate Variability biofeedback tool you can train in 8 weeks reaching positive results: more resilience and better self-regulation by balancing your Autonomic Nervous System (ANS) with guided breathing. Guiding the resonance frequency can be compared with guiding someone on a swing by pushing at just the right moment to optimize their swing. Stresseraser Pro is a free app for iPhone that can be used as a mobile heart rhythm biofeedback device jointly with a monitoring sensor.