iOS 17.0+ · APPLE WATCH · HEALTHKIT · 7-DAY BASELINE · $4.99/MO
Tensly: Apple Watch Stress Monitor — Know Your Stress Before You Feel It
Your body signals stress before your mind does. Tensly monitors your heart rate and HRV throughout the day, learns your personal baseline in 7 days, then quietly detects when your nervous system is under strain.
Requires iOS 17.0+ · Apple Watch Series 4+ · watchOS 10.0+
7-day personalized baseline
Tensly spends the first 7 days learning your normal HRV and heart rate patterns across different times of day and activity states. Then it knows what elevated looks like — for you.
- →7-day passive learning from your existing Watch data
- →Accounts for time of day and activity state
- →Sleep quality factored into baseline
- →Stress detection activates after baseline is established
Passive monitoring, no extra battery drain
Tensly uses the same HealthKit data your Watch already collects passively. No additional sensors are activated, no background processes added. Most users report no noticeable battery impact.
- →Uses existing HealthKit data — no extra sensor activation
- →No measurable battery impact on Apple Watch
- →Continuous passive monitoring throughout the day
- →Accounts for sustained duration, not just single readings
Gentle, configurable nudges
When Tensly detects sustained nervous system strain, it sends a gentle nudge — not an alarm. Notifications are fully optional with a daily cap, quiet hours, and a complete off switch.
- →Gentle nudges — not alarms or anxiety-inducing alerts
- →Configurable daily cap: 1–5 nudges maximum
- →Custom quiet hours for undisturbed periods
- →Turn off notifications and still keep monitoring active
Questions
Frequently asked questions
Does Tensly drain my Apple Watch battery?
No. Tensly uses the same HealthKit data your Watch already collects passively. No additional sensors are activated, no background processes are added. Most users report no noticeable battery impact.
How accurate is the stress detection?
Tensly uses a weighted statistical model comparing your real-time HRV and heart rate against your personal baseline. It accounts for time of day, activity state, sleep quality, and sustained duration — not just a single reading. It reflects your nervous system's physiological state, not your emotions or thoughts.
Is there a free trial?
Yes. Tensly includes a 7-day free trial. During this period you'll complete baseline learning and experience the full app. Stress detection activates after your baseline is established. No charge until day 8 — cancel anytime during the trial at no cost.
Can I turn off notifications?
Yes. Nudges are completely optional. You can disable all notifications, adjust the daily cap (1–5 nudges), set custom quiet hours, or keep monitoring active with no alerts at all. All configurable in Settings.
What happens to my data?
Everything stays on your device. Tensly processes all data locally using Apple's HealthKit framework. No cloud storage. No analytics. No data sharing with third parties. No account required.
Can I use Tensly without an Apple Watch?
No. Tensly requires continuous HRV and heart rate data, which is only available through Apple Watch via HealthKit. iPhone alone does not provide sufficient signal quality for accurate detection.
What Apple Watch models are supported?
Apple Watch Series 4 or later. watchOS 10.0 or later required. Series 4 introduced the electrical heart sensor used for HRV measurement.
Is Tensly a medical device?
No. Tensly is a wellness and self-awareness tool. It does not diagnose, treat, cure, or prevent any disease or condition. Always consult a qualified healthcare provider for medical or mental health concerns.
Know your stress before you feel it
Try Tensly free for 7 days. Personal baseline stress detection using your Apple Watch data — with complete privacy and configurable nudges.
Download on the App Store7-day free trial · $4.99/month · Apple Watch required