Support
Last updated: 18 June 2026
Need a hand with CardialOS? Email us at resources@thetinyapp.com and we'll get back to you. The answers below cover the most common questions.
How does CardialOS get my data?
CardialOS reads health and fitness data from Apple Health on your device — heart rate, resting heart rate, heart-rate variability (HRV), VO₂max, respiratory rate, blood oxygen, sleep, and your workouts. On first launch you'll see a "Connect Apple Health" screen and an Apple Health permission sheet; grant access there. Everything is processed on your device.
I connected, but a metric or tile is empty. Why?
A reading only appears when the data behind it exists in Apple Health, so the most common reasons are:
- No source for that metric. Most readings come from an Apple Watch. HRV, VO₂max, resting heart rate, blood oxygen, and sleep need a Watch (and time wearing it) to populate.
- Some types are Apple-Watch-only or read-only. Exercise minutes and wrist temperature are written by the Watch and can't be supplied by other apps, so they may stay empty without one.
- A few features need your profile. Training heart-rate zones, training load, strain, and cardiovascular age need your age, sex, weight, and threshold heart rate. Set these in Profile and the related screens fill in.
- Give it time. Trends (recovery, load, VO₂max) get more accurate over days and weeks as more data accumulates.
How do I review or revoke CardialOS's access to Health?
On iOS: Settings → Health → Data Access & Devices → CardialOS. You can turn individual data types on or off there at any time. CardialOS only ever reads your health data.
Is my data private?
Yes. Your health data stays on your device — CardialOS has no account and no sign-in, and we never receive, store, or transmit your health values. We do collect anonymized product-usage and crash diagnostics to keep the app working well, never your health data. Details are in our Privacy Policy.
Is CardialOS a medical device?
No. CardialOS is a personal fitness and wellness tool. It does not diagnose, treat, cure, or prevent any condition, and it is not a substitute for professional care. Always consult a qualified professional about your health.
Still stuck?
Email resources@thetinyapp.com with your device model and iOS version and a short description of what you're seeing, and we'll help.