Privacy Policy for Cairn Skin

Last updated: August 3, 2026

The short version

Cairn Skin does not collect, transmit, or store any of your data outside your own device. There is no account, no server, no analytics, and no advertising. Your photos stay on your iPhone.

What Cairn Skin stores

Everything below is saved only in the app's private storage area on your device:

Photos you take in the app
Notes you attach to those photos
Tracking area names you create
Image comparison data, a numeric summary of each photo, generated on your device, used to compare photos to each other

What Cairn Skin does not do

No account or sign-in. There is nothing to register for.
No servers. Cairn Skin has no backend. Your data is never uploaded anywhere.
No analytics or tracking. No usage data, crash reporting, device identifiers, or advertising identifiers are collected.
No third-party services. No SDKs that collect data are included.
No iCloud sync. Your photos are not backed up to iCloud by the app itself.

Permissions the app requests

Camera, to take tracking photos. Photos are saved only to the app's private storage.
Motion & Fitness, reads the gyroscope to tell you when the phone is steady enough for a clear photo. This data is used momentarily and never stored.
Face ID / Touch ID, to unlock the app. Biometric authentication is handled entirely by iOS; Cairn Skin never receives or stores your biometric data.

Photo analysis

Image comparison happens entirely on your device using Apple's Vision framework. No image is ever sent to a server, cloud service, or third party for analysis.

Exporting a PDF

Cairn Skin can generate a PDF of a tracking area on your device. The app does not send that file anywhere, after it is created, you choose what to do with it through the standard iOS share sheet. Once you share a PDF outside the app, this policy no longer governs it.

Deleting your data

You can delete individual photos, entire tracking areas, or everything at once (Settings → Delete All Data). Deleting the app from your device also removes all of its data permanently.

Children

Cairn Skin is not directed at children under 13 and does not knowingly collect information from anyone.

Not a medical service

Cairn Skin is a personal wellness journaling tool. It does not diagnose, screen for, or assess any medical condition, and it is not a substitute for professional medical advice. Consult a qualified healthcare provider about any health concern.

Changes to this policy

Any future changes will be posted on this page with an updated date.

Contact

Questions about this policy: [YOUR EMAIL HERE]