Substrata is an environmental health intelligence app that layers environmental data — weather conditions, barometric pressure, noise exposure, and more — alongside your health data from Apple Health to highlight possible hidden associations linked with your wellbeing. It includes a headache tracking and trigger identification system, a statistical correlation engine, and comprehensive weather monitoring — all processed entirely on your device.

Substrata is not a medical device. It does not diagnose conditions, provide medical advice, or replace professional healthcare guidance. Please speak to a healthcare professional about any health concerns.

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Frequently Asked Questions

What data does Substrata track?

Substrata monitors environmental conditions (weather, barometric pressure, temperature, humidity, UV index, wind, daylight hours, moon phase) via Apple Weather, and health data (sleep quality, heart rate, HRV, resting heart rate, respiratory rate, blood oxygen, wrist temperature) via Apple Health. If you have an Apple Watch, it also reads environmental noise exposure levels. You can also log headaches to help identify personal triggers.

What health data does Substrata access?

With your permission, Substrata reads sleep analysis, heart rate, heart rate variability (HRV), resting heart rate, respiratory rate, blood oxygen, wrist temperature, and audio exposure levels from Apple Health. This data is read-only — Substrata never writes to or modifies your health data.

How does the correlation engine work?

After collecting at least 14 days of data, Substrata uses on-device statistical analysis (Bayesian regression) to highlight potential links between environmental conditions and your health metrics. All analysis runs entirely on your iPhone — no data is sent anywhere. Correlations tend to become more dependable with more data (around 30+ days for more reliable patterns, 60+ for fuller analysis).

Does Substrata send my data anywhere?

No. All data processing happens entirely on your device. The only network requests are to Apple Weather for weather conditions. Substrata has no servers, no cloud storage, no user accounts, and no analytics or tracking. Your data does not leave your iPhone.

Does Substrata use my location?

Location is used to fetch local weather data from Apple Weather and optionally for zone detection (for example, home, work). Weather uses an approximate location. Zone detection, if you set up zones with a location, asks for a location accurate to about 100 metres; zone centres are rounded to about 110 metres before they are saved and stay on your iPhone. You can use the app without location access, but weather data will not be available.

How do I manage permissions?

You can manage all permissions (health data, location, notifications) in the iOS Settings app under Substrata. You can withdraw any permission at any time without affecting other features of the app.

What happens to my data if I delete the app?

All Substrata data is stored locally on your device. When you delete the app, all associated data is permanently removed by iOS. There is nothing to delete from any server because no data is ever transmitted off your device.

What iOS version is required?

Substrata requires iOS 26.2 or later and is designed for iPhone.

Does Substrata work with Apple Watch?

Apple Watch tends to enhance the experience significantly — it provides environmental noise levels (dBA), heart rate, HRV, respiratory rate, blood oxygen, and wrist temperature. Without a Watch, Substrata still works with weather data, sleep duration, headphone audio, and activity classification.

What is the headache tracker?

You can log headache events with severity and type (migraine, tension, cluster). After logging around 20–30 events, the correlation engine tends to highlight your personal environmental triggers and can alert you when conditions appear similar to past headache patterns. This feature is not medical advice.

Privacy

Your privacy is fundamental to Substrata's design. For complete details about how we handle your data in line with applicable data protection laws, including UK GDPR, please read our Privacy Policy.

App Information

• Developer: Kynoss Studios
• Platform: iPhone (iOS 26.2+)
• Category: Health & Fitness