CALM! is a mindfulness app that supports self-care based on heart rate variability (HRV).

By placing your finger on the smartphone camera for 30 seconds, the app estimates heart rate variability (HRV) from optical pulse signals.

HRV has been internationally studied in relation to stress and relaxation, and CALM! provides this estimated value as reference information to support daily self-care and mindfulness practice.

Depending on your condition, the app suggests techniques such as bilateral stimulation and box breathing. 

You can also choose from multiple frequencies and environmental sounds tailored to your needs—whether you want to relax, focus, or fall asleep. Combined with daily mood logging, CALM! helps you find the best condition for your well-being.

Features
•Reference display of autonomic nervous system state based on HRV analysis
•Mindfulness sessions using bilateral stimulation
•Box breathing and relaxation sound guidance
•Mood tracking and history review

Subscription
•$1.99per month (with a 3-day free trial)
•Premium subscription unlocks the following features:
・Detailed analysis reports
・Storage and comparison of measurement history
・Access to all mindfulness sessions, breathing methods, and sound content
•Cancel anytime

- Supported Environment
This app is only compatible with devices equipped with a flash and running iOS 14 or later.
Please note that operation on iPads or iPhones that do not meet the above requirements is not covered by support.

Disclaimer
•This app provides reference information based on HRV analysis and is not a medical device intended for diagnosis, treatment, or prevention of disease.
•Please consult a healthcare professional when medical judgment or treatment is required.

References
•Selvaraj N, et al. Validation of Smartphone PPG for HRV Measurement. Frontiers in Digital Health. 2024.
•Task Force of the European Society of Cardiology and the North American Society of Pacing and Electrophysiology. Heart Rate Variability: Standards of Measurement, Physiological Interpretation and Clinical Use. Circulation. 1996.

Terms of Use: https://tnq-tech.web.app/term_of_use