ISYTHENICS

Privacy Policy

Last updated: August 15, 2026

Your privacy is protected by design.

Summary

Isythenics runs entirely on your device. We have no servers, no databases, no accounts, no analytics, and no third-party tracking. Your information — including your health data — is never transmitted off your device and never shared with third parties.

What We Collect

Nothing reaches us. There is no server to collect it — no personal data, behavioral data, or identifying information is ever sent to us or to any third party. Health data is read and written only on your device, through Apple's HealthKit, and is covered in Health Data below.

Local Data Storage

Your preferences and workout settings are stored locally on your device using iOS's standard storage mechanisms (UserDefaults). This information includes your enabled and disabled exercises, your workout timing preferences, your sound and haptics preferences, the time since your last workout, and your acceptance of the disclaimer. This data never leaves your device and is automatically deleted if you uninstall the app.

Health Data

Isythenics includes an Apple Watch companion that works with Apple's HealthKit. During a workout on the watch, the app reads your heart rate and shows it to you live on your wrist. It does not store your heart rate, and it does not send your heart rate to your iPhone — that reading never crosses between your devices.

When you complete a workout, the app writes it to HealthKit so it counts toward your Activity rings. Heart rate is read only on Apple Watch.

Isythenics never transmits your health data off your device, never uses it for advertising, and never shares it with anyone. Your health information is handled entirely on your device, through HealthKit.

Apple Watch and Device Sync

When you use the Apple Watch companion, your iPhone and watch stay in step over Apple's WatchConnectivity framework — a direct, device-to-device link, not the internet. This sync carries only exercise names, workout timing, pacer state, and your settings. It carries no health data.

Third-Party Services

Isythenics does not use any third-party services. We do not integrate with analytics platforms, advertising networks, social media services, or crash-reporting tools. The app communicates only with Apple's standard operating system services on your device.

Notifications

If you grant permission, Isythenics sends local notifications during workouts to alert you when exercises change. These notifications are generated and processed entirely on your device. No notification data is sent to any server.

Children's Privacy

Isythenics does not knowingly collect any data from anyone, including children under the age of 13. The app contains no advertising and does not require an account.

Changes to This Policy

If we update this privacy policy in the future, we will post the updated version on this page with a new "Last updated" date. Material changes will be communicated through the app.

Contact

Questions about this privacy policy? Contact us at support@isythenics.com.

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