Privacy policy

Compound · last updated 2 August 2026

Compound does not collect any data.

There are no accounts, no analytics, no advertising, no trackers, no third-party SDKs, and no servers of mine. Everything the app knows about you stays on your own devices, where I can’t see it.

Your training data

Your workout history, progression numbers, exercise choices and settings are stored as files on your iPhone, inside the app’s private storage. They leave your device in exactly two ways, both of which you control:

• Your own device backups — iCloud or a computer — which Apple manages and encrypts under Apple’s privacy policy.
• Live syncing to your own paired Apple Watch, described below.

Deleting the app deletes this data. No copy is kept anywhere else.

Apple Watch

During a workout the iPhone app sends the session state to Compound on your paired Apple Watch, and the watch sends your taps back. That runs over Apple’s device-to-device Watch Connectivity link between your two devices. It does not pass through a server of mine, because there isn’t one.

Apple Health

Health access is optional and asked for through the standard iOS permission screen. If you grant it, Compound:

• Saves completed workouts to Apple Health — activity type, start and end time, and, when the watch runs the session, the heart rate and active energy it measures.
• Reads heart rate and active energy during a live workout, only to show them on screen while you train.

Health data stays inside Apple Health on your devices. Compound never transmits it, never uses it for anything besides the workout in front of you, and never shares it. You can revoke access at any time in Settings → Privacy & Security → Health → Compound, and the app keeps working without it.

Notifications

Notifications are optional and local. They are scheduled on your device — when a rest timer ends while the app is in the background, for instance — and never come from a server. Compound has no push-notification infrastructure and no device token.

Purchases

Compound is sold through the App Store, and Apple handles the purchase and any payment information. I never see your name, address or payment details, and receive only Apple’s aggregate sales reports.

Children

Compound is suitable for all ages and collects no data from anyone, including children under 13.

Changes

If this policy changes, the updated version will be posted at this address with a new date, before the version it describes ships.

Contact

Questions about this policy: [email protected].