Shift

Privacy Policy

Shift is built around a single promise: your health data never leaves your iPhone.

The short version

• We do not run any servers that receive your health or travel data.
• There are no accounts and no sign-up. We never see who you are.
• We do not use third-party analytics, ad SDKs, crash reporters that include user data, or any tracker that fingerprints your device.
• Every estimate (circadian phase, adaptation forecast, daily protocol) is computed entirely on your iPhone.
• Subscription billing is handled by Apple — Apple sees the transaction; we never do.

Data we read from Apple Health

With your explicit permission, Shift reads (read-only) the following types from HealthKit on your device:

Category	Specific types
Temperature	Apple Sleeping Wrist Temperature (the core signal we model)
Sleep	Sleep analysis (in-bed, awake, core, deep, REM)
Cardio	Heart rate, heart rate variability (SDNN), resting heart rate
Respiration	Respiratory rate
Daylight & activity	Time in daylight, workouts
Optional context	Dietary caffeine (when you log it)

If you enable our wind-down feature, Shift writes a Mindful Session entry for the duration you spent winding down. That is the only thing Shift ever writes back to Apple Health.

Data we store locally

Shift stores your baseline circadian model, adaptation profile, and trip history in your app's local Application Support directory. This data:

• stays in the app's sandbox on your device
• is deleted when you delete the app
• is included in your iCloud / encrypted iTunes backup only if you have those backups enabled — Apple controls that, not us

The on-device store contains derived metrics — your nightly cosinor fit, sleep midpoints, daily phase estimates, trip records — not raw HealthKit samples.

What we don't collect

• No personal identifiers, no email, no name, no IDFA, no IDFV-based tracking.
• No location data unless you explicitly enable "confirm arrival" (coarse city-level only, computed on device, never transmitted).
• No advertising, no behavioral analytics, no crash log uploads that contain your data.

Time zone and barometric sensors

Shift watches your device's time zone changes and (with your permission) altimeter readings to auto-detect that you're on a flight. Both of these are read on-device, used to update the active protocol, and not transmitted anywhere.

Subscriptions and purchases

Subscriptions (Shift+) and one-time purchases (Trip Pass) are sold through Apple's App Store. Apple processes the payment, holds the receipt, and tells your device whether the entitlement is active. Shift never sees your name, card details, or Apple ID. Cancel at any time from Settings → Apple ID → Subscriptions on your iPhone.

Children

Shift is intended for adults who travel for work. It is not directed to children under 13.

Wellness, not medical

Shift estimates circadian phase to suggest behavioral cues (light, sleep, caffeine). It does not diagnose or treat any condition and is not a substitute for medical advice. If you have a clinical sleep disorder, please talk to a sleep medicine specialist.

Changes to this policy

If we ever change this policy, we'll update the "Effective" date at the top and document substantive changes in the app's release notes. We will never retroactively reduce the privacy protections in place for previously collected data.

Contact

Questions? Email info@hashingcorp.com.

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