1
Morning check-in
Overnight heart rate variability, resting heart rate and sleep from your Apple Watch, compared with your own last 14–28 days. No population norms, no red numbers. Just where today sits against your usual.
Pace your energy with the Apple Watch you already own.
Slowtide turns your overnight heart data and your own two-tap notes into a daily energy budget. Built for people living with POTS, dysautonomia, ME/CFS and long COVID. No extra wearable to buy. Your health data stays on your phone.
Join the waitlist and help shape the beta. No spam, one email when it is your turn.
This morningTue
Overnight HRV41 msin your usual range
Resting heart rate68 bpma bit above your usual
Sleep6 h 40close to your usual
Today’s energy budgetbased on your last 28 days
Your overnight numbers lean toward a lighter day. You decide what that means.
What Slowtide does
2
Day budget on your wrist
Minutes spent above your usual heart-rate zone, as a complication on your watch face and on your lock screen. Start an activity session for the shower, the grocery run or the school pickup and feel a tap when you drift above your usual zone.
3
Notice the patterns
Two-tap logging for symptoms and heavy days, with presets written for POTS and for delayed payback (PEM). A weekly view shows how your days connect, one or two days apart. One button makes a PDF you can bring to your clinician.
Why we are building this
No extra armband
Other pacing apps ask you to buy their own sensor. The Apple Watch already records overnight heart rate variability and resting heart rate every night. Slowtide reads what you already have.
Written for brain fog
Large type, dark mode, two taps to log anything, nothing hidden behind menus. If you can glance at your wrist, you can use it.
Your data stays yours
Health data lives on your iPhone, not in our cloud. We do not sell data, run ads, or use your health data for marketing. Ever.
Honest about what it is
Slowtide shows your own numbers and your own notes so you can plan your day and talk with your clinician. It does not give medical advice and it is not a medical device.
Your energy profile
Nine quick questions, about two minutes. We use your answers to shape the beta and to show which part of Slowtide would matter most to you.
Questions people ask
Is this medical advice?
No. Slowtide is not a medical device and does not give medical advice. It shows your own data so you can talk about it with your clinician. It does not tell you whether a number is good or bad, and it will not tell you what to do about your medication or care.
Which conditions is it for?
We are starting with POTS and other forms of dysautonomia, then ME/CFS and long COVID. If you live with fatigue or orthostatic symptoms from another cause and pacing is part of your day, the quiz will still work for you.
What do I need?
An iPhone and an Apple Watch running watchOS 11 or later. Overnight HRV and resting heart rate come from wearing the watch to sleep. Other wearables (Garmin, Oura, Fitbit, Whoop) are not supported at launch. There is no Android version yet.
What will it cost?
We plan a single subscription of about $70 a year, or $10 a month, after a free 7-day trial with everything unlocked. No free tier with locked features, no ads, no selling data. Early waitlist members get the first year at a lower price.
When can I use it?
Private beta on TestFlight in January 2027 for waitlist members, starting with people who join the interviews. App Store release after that.
Who is building it?
A very small team. We are looking for a patient co-founder or ambassador and a clinician advisor who works with POTS. If that could be you, say so in the quiz.