A pacing app for chronic illness. iOS and Apple Watch.
Understory tracks your energy in spoons, reads your heart rate variability each morning, and helps you see patterns over time. Your health data never leaves your device. No servers we operate ever touch it.
§01 Features
Not step counts. Not workout streaks. Spoons, morning stability, and patterns over time.
01
Watch · daily
A short guided reading on Apple Watch captures heart rate variability and resting heart rate. Paired with a quick subjective check-in. Together they give you a stability score that reflects how today actually started.
02
Phone · core
Your energy is measured in spoons. Not a fixed number. Not a score against some standard. Your ceiling is calibrated to you during onboarding and adapts over time. Categories and costs are yours to adjust.
03
Watch · ambient
Background heart rate monitoring notices sustained elevations without running an all-day workout session. Unusual activity surfaces quietly in your evening digest. Not as a real-time alarm.
04
Watch · gesture
A dedicated button on the Watch face for moments that happened before you could plan for them. One tap logs the event. You can add notes and adjust timing later.
05
Phone · daily
Log symptoms with severity, track medications and timing. The app surfaces your most-logged entries for quick access. No typing required on bad days.
06
Phone · automatic
When post-exertional malaise hits, the app looks back 72 hours and identifies which sessions may have triggered it. Over time, patterns emerge. You learn which activities carry delayed cost.
07
Phone · evening
One quiet notification at the end of the day. What happened, what it cost, anything that looked unusual. Not a score. Not a grade. A factual summary you can read or ignore.
08
Phone · optional
Generate a time-limited bundle for a doctor or loved one. You choose exactly what is included. It is sealed on your device. They open it in a browser using a passphrase you give them. No account needed.
09
Phone · ongoing
Trends in stability, session frequency, and symptoms. Described factually. A line on a chart that you read as you choose. No push notifications about what the data means.
Your day
The app is quiet. It fits around your day, not the other way around.
Community
POTS Postural orthostatic tachycardia syndrome
ME/CFS Myalgic encephalomyelitis / chronic fatigue syndrome
Long COVID Post-acute sequelae of SARS-CoV-2
EDS Ehlers-Danlos syndromes
MCAS Mast cell activation syndrome
Fibromyalgia Chronic widespread pain and fatigue
Dysautonomia Autonomic nervous system dysfunction
And the long tail Any condition where energy is finite and pacing matters
If you pace, it's for you.
§02 Privacy
Most health apps send your data to servers. Understory does not. Everything stays on your device and in your personal iCloud, encrypted by Apple's systems. We can't see it. No one else can either.
Ring 0
Your device and iCloud (default)
All health data lives locally in SwiftData and syncs to your personal iCloud. End-to-end encrypted by Apple. No servers we operate ever touch it. The app works fully offline.
Ring 1
Care-team sharing (your choice)
You can generate an encrypted bundle for a doctor or loved one. The bundle is sealed on your device before it leaves. We store ciphertext only. Decryption happens in the recipient's browser using a passphrase you share with them directly.
Ring 2
Community baselines (planned, opt-in)
An optional, future feature: see how your patterns compare to anonymous group averages of people with similar conditions and baselines. Only group totals would ever leave your device. Your individual readings never do. A group has to include at least 50 people before any number is shared. This is not in the current release; turning it on, if and when it ships, will always be your choice.
§03 Screens
Real screenshots arrive with the launch build. These frames hold the place.
Today
Morning reading
Session log
Trends
Care-team bundle
§04 A dedication
Built by someone who isn't sick, for the person they love who is.
There are days she can't quite explain how she's doing, and days I can't tell just by looking. I know the particular helplessness of loving someone whose pain isn't visible to anyone else. I can't carry it for her. But I could try to build something that sits beside her while she carries it.
Understory is that small thing. It describes how you feel. It doesn't evaluate. It trusts your experience, even when the biometrics disagree. It's quiet on bad days. It's built for the community that already speaks the language of spoons: Long COVID, POTS, EDS, MCAS, ME/CFS, fibromyalgia, and the long tail of conditions the world doesn't always see.
§05 FAQ
No. The app works fully offline. iCloud sync and care-team sharing both require a network connection, but logging sessions, completing a morning reading, and viewing your data do not.
Nowhere we operate. Health data lives on your device (SwiftData) and in your personal iCloud, which is end-to-end encrypted by Apple. We cannot read it. We have no server that touches it during normal use.
If you share a care-team bundle, we temporarily store an encrypted file. We never see its contents. The file expires when you revoke access.
Spoon theory is a framework developed by Christine Miserandino in 2003 to describe the limited, finite energy available to people living with chronic illness. It has become widespread in the POTS, EDS, ME/CFS, MCAS, and Long COVID communities. Understory uses spoons as its energy unit because the community already speaks that language.
During onboarding, the app asks you to describe a typical good day, a typical hard day, and activities that feel manageable versus too much. From those answers it proposes an initial daily ceiling and per-category costs. Both are editable immediately and at any time. The app adapts them slowly over the following months based on your actual patterns.
There is no hardcoded ceiling. There is no standard cost for any activity. The numbers are yours.
An Apple Watch unlocks the morning reading and session capture features. iPhone-only use is possible: you can log sessions, symptoms, and medications manually, and view trends. The Watch is recommended but not required to get value from the app.
No. Understory describes patterns in your data. It does not diagnose, treat, or make medical recommendations. It is a pacing and self-knowledge tool, not a medical device. Please work with your care team for anything clinical.
Pricing has not been finalised. This page will be updated before launch. The app will not use a "log more to unlock" model. Core pacing features will not be gated behind a paywall.
From the You tab in the app, account and data deletion takes effect immediately on your device, propagates via CloudKit within minutes, and revokes all active care-team shares. No questions asked. Full data export (JSON) is also available from the same screen at any time.