Questions, answered plainly.
Everything you need to know about Sereno, Apple Watch support, and your data.
About Sereno
What is Sereno?
Sereno is an iOS app built around Apple Watch and Apple Health. It turns biometric signals, sleep, activity, and daily context into a readable 0-100 stress score, guided resets, and weekly pattern readings.
How does the stress score work?
Your score combines over 20 signals, including heart rate variability, resting heart rate, sleep quality, activity levels, time of day, and calendar events. It's compared against YOUR personal baseline, not population averages. Learn more on our scoring page.
Is Sereno a medical device?
No. Sereno is a wellness tool, not a medical device. It does not diagnose conditions, replace medical advice, or make health claims. If you're concerned about your health, please consult a healthcare professional.
Privacy & Data
Does Sereno access my health data?
Yes, with your explicit permission. Sereno reads heart rate, HRV, sleep, and activity data from HealthKit. This data stays on your device — we never upload your health data to our servers.
What data does Sereno collect?
Anonymous usage analytics (which screens you visit, not what your score is) and optional diagnostic reports for troubleshooting. No health data, no personal identifiers. See our privacy policy for details.
Can I delete my data?
Yes. You can delete all your Sereno data from the app's Profile tab. HealthKit data is managed separately through Apple's Health app.
Subscriptions & Pricing
Is Sereno free?
Core stress tracking, basic trends, and box breathing are free forever. Premium ($6.99/month or $39.99/year) adds weekly readings, detailed reports, and the full guided reset library.
How do I cancel my subscription?
Through your Apple ID settings: Settings > [Your Name] > Subscriptions > Sereno. No cancellation fees, no hoops to jump through.
Is there a free trial?
Yes. Premium includes a 7-day free trial. You won't be charged until the trial ends, and you can cancel anytime during the trial.
Apple Watch & Setup
Do I need an Apple Watch?
Sereno is built around Apple Watch and Apple Health. The best experience uses Apple Watch for continuous signals and watch-based guided resets.
What does setup look like?
Download Sereno, allow Apple Health access, and keep your Apple Watch on as usual. Sereno starts reading the signal already present in your day.
Science & Accuracy
Is the stress score accurate?
Sereno's score combines over 20 parameters across biometrics (HRV, heart rate), behavior (sleep, activity), and context (time of day, meetings, weather). HRV is one of the strongest signals, but the multi-signal approach is what makes the score reliable. It builds a personal baseline from your data over 7-14 days. The score is a useful wellness signal, not a medical diagnosis. Learn how scoring works.
What research is Sereno based on?
Sereno's scoring draws on published HRV and stress research, including work by Thayer, Chalmers, Shaffer & Ginsberg, and Lehrer & Gevirtz. We cite specific studies on our scoring page.
What happens when my stress score is very high?
When your score reaches elevated levels, Sereno adjusts its interface to prioritize calming tools. You will see a guided breathing exercise and quick access to crisis support hotlines for 12 countries (available offline).
Important: Sereno is a wellness awareness tool. It does not diagnose or treat any condition. If you are experiencing a mental health emergency, please contact emergency services or a crisis helpline directly.
