SlowpulseSlowpulse for iPhone & Apple Watch
Your body notices stress before you do.
Slowpulse learns what your heart does when you're calm — then tells you when it stops doing that, and walks you back down with a breath.
Coming soon to the App Store · currently in TestFlight beta
Inhale
How does it work?
Built on your baseline, not a population average.
A resting heart rate of 72 means nothing on its own. It means something if yours is normally 58.
It learns your normal
Two weeks of resting heart rate and HRV from Apple Health become your personal baseline. Wear your watch overnight and it settles on its own.
It watches for drift
Your watch streams heart rate and HRV. When your pulse climbs and your variability drops at the same time, that pairing is the signal.
It knows exertion isn't stress
A hard workout raises your heart rate too. Slowpulse discounts the score using active energy and exercise minutes, so a run doesn't read as panic.
It gives you the breath
A guided 4-7-8 cycle with haptics on your wrist. Inhale for four, hold for seven, exhale for eight. No screen required.
On the wrist
The part that matters happens without your phone.
The Apple Watch app reads heart rate and HRV directly, shows your current score, and runs the full breathing exercise with a distinct haptic for each phase — one tap up to inhale, a click to hold, one tap down to exhale.
- Live heart rate and HRV from the wrist sensor
- Your stress score mirrored from iPhone
- Guided 4-7-8 with per-phase haptics
- Works while the phone stays in your pocket
Privacy
Nothing leaves your device. There is nowhere for it to go.
Slowpulse has no account, no server and no analytics. Your heart data is read from Apple Health, scored on your iPhone, and stored on your iPhone. The app makes no network requests of any kind — the only thing it talks to is Apple's own payment system, when you choose to subscribe.
- No sign-up, no email, no password
- No backend to breach — none exists
- No third-party analytics or tracking SDKs
- Delete the app and the data goes with it
A stress app that phones home is a strange thing to trust.
You can verify the claim the boring way: put your iPhone in Airplane Mode. Everything still works.
Read the privacy policyOur pricing plans
Checking your score is always free.
You only pay for the part that works when you aren't thinking about it — being told, and being able to look back.
Free
$0
No account required
- Check your stress score any time
- Guided 4-7-8 breathing, iPhone and Watch
- Your five most recent events
- Everything stays on-device
Premium
$29.99
per year · renews annually
- Everything in Free
- Stress alerts the moment you drift
- Complete history and trends
- Still entirely on-device
Lifetime
$79.99
once · no subscription
- Everything in Premium
- One payment, kept forever
- All future updates included
- Nothing to remember to cancel
Prices in USD. Payment is charged to your Apple Account; cancel any time in Settings. See Terms.
Why it's built this way
HRV is unusually revealing.
Over weeks, heart rate variability sketches your sleep, your drinking, your illnesses and your bad days at work. Most apps in this category upload it, because uploading it is what makes a dashboard, a leaderboard and a recommendation engine possible.
Slowpulse doesn't do those things, and so it doesn't need the data anywhere but your phone. The scoring is a handful of arithmetic on numbers Apple Health already holds — it does not need a model in a data centre to run. Keeping it local wasn't really a feature decision so much as the absence of a reason to do otherwise.
Slowpulse is in beta.
Finished enough to use daily, and not yet on the App Store. If you'd like a TestFlight invite, or a note when it launches, say hello.