SteadyDay is built around a strict privacy principle: your health data stays on your iPhone. We do not operate a backend server. We do not transmit, store, or analyze your health information off your device.
With your permission via Apple's HealthKit consent prompt, SteadyDay reads the following data types from the Health app:
These reads happen on your device and the resulting computations (your daily capacity score, activity budget, alerts) are stored locally in the SteadyDay app's sandbox.
All app data is stored in a SwiftData container on your device. Nothing is uploaded to a server. Categories of stored data:
SteadyDay offers an optional "SteadyDay Plus" upgrade with two tiers: an annual subscription with a 7-day free trial, and a one-time lifetime purchase. These purchases are processed entirely by Apple via StoreKit. Apple receives your payment information; SteadyDay does not. Apple provides us with anonymized aggregate sales data only.
If you enable the caregiver sharing feature, your sharing preferences are stored locally on your device. This feature does not currently transmit data to anyone — it is preparatory scaffolding for a future opt-in remote-share feature, which will require an additional consent step before any data leaves your device.
If you complete a 6-minute walk test, SteadyDay stores the raw heart-rate samples captured during that walk on your device, plus the derived anaerobic-threshold estimate. You can view these in the CPET History screen and delete them per session or in bulk at any time. They never leave your device and are never shared with caregivers or any third party.
SteadyDay is not directed at children under 13. We do not knowingly collect any data from children under 13.
If we change this policy, we will update the "Effective date" at the top and post the new version at the same URL. Material changes will also be surfaced in the app's onboarding flow.
Questions, concerns, or data-deletion requests:
Convergent Systems Co.
thomas@convergent-systems.co