Last updated: September 2026
Proof Skincare is built on a simple rule: your face and your skin data belong on your iPhone, not on our servers. This policy explains exactly what stays on your device, the small amount of anonymous data that doesn’t, and why.
Proof Skincare has no user accounts, no sign-in, and assigns you no identifier. We could not link data to you even if we wanted to — there is no “you” in our systems.
Proof Skincare is a camera-based skin measurement app, so this section states exactly what it does with face data. It is written to be read literally.
What face data Proof Skincare collects. Three things, all created on your iPhone:
What Proof Skincare does not do. Proof Skincare does not perform face recognition or face identification. It does not create, derive or store a faceprint, face template, or any biometric identifier. It cannot recognise you, match you to another photo, or tell one person from another. It does not use Face ID, ARKit face tracking, or the TrueDepth camera. Face data is never used for authentication, advertising, profiling, or training any model.
Where face data is stored. Entirely on your iPhone. Scan photographs are stored in the app’s private container with iOS file protection enabled. Measurements are stored in the app’s local database on the same device. Proof Skincare has no user accounts and no server-side storage of any kind for face data — there is no copy of your photographs or face data on our servers, because they are never sent there.
Sharing with third parties. Proof Skincare never transmits your photographs, your face landmarks, or any image of you to us or to any third party. The only data that ever leaves your device is described in the section below, and it consists of numbers and text you entered — never an image. There is no analytics SDK, no advertising SDK, and no third-party service that receives face data.
Two actions can move a photo off your device, and both are started by you, one at a time, with the destination chosen by you:
How long face data is retained. For as long as you keep it, and no longer. Proof Skincare applies no expiry and performs no automatic deletion, because the value of the app is your own history over time. You can delete individual data or everything at once, at any time, using Settings → “Delete everything”, which erases every photograph, measurement, experiment and profile detail from the device immediately and irreversibly. Deleting the app from your iPhone also removes all of it. Because Proof Skincare holds no copy on any server, deletion on your device is complete deletion — there is nothing left for us to delete, and nothing for us to return.
Three features talk to a server. None of these requests includes your name, an account, your photos, or any device identifier.
Verdict narration. When you conclude an experiment, the numeric results (for example: “redness −2.4, high confidence”) and the experiment’s title (for example: “Added niacinamide serum”) are sent to our server, where an AI model turns those numbers into a short written explanation. The numbers and title are processed to generate that text and are not stored as content; we retain only technical metadata (processing time and cost) to operate the service.
Product barcode lookup. When you scan a product barcode, the barcode alone is sent to look up that product’s name, brand, and ingredients. Nothing else is sent, and nothing about your shelf is uploaded: products you add or edit stay on your device. Proof Skincare has no way for users to write to its product database.
Weather context (optional, off by default). If you switch on “Record the weather with each scan” in Settings, Proof Skincare asks iOS for your approximate location at the moment of a scan and sends it to Apple’s WeatherKit service to look up the temperature, humidity and UV index. Proof Skincare never asks for your precise location, and your location is never stored — only those three weather values are saved with that scan, on your device. Weather data is provided by Apple Weather; Apple’s use of this data is governed by Apple’s own terms, available at https://weatherkit.apple.com/legal-attribution.html. Switching the setting off stops this entirely.
If you never conclude an experiment, never scan a barcode, and leave weather recording off, Proof Skincare sends nothing at all.
Proof+ subscriptions are processed entirely by Apple through your Apple Account. We receive no payment details and no purchase history tied to you. Manage or cancel anytime in your Apple Account settings.
Settings → “Delete everything” erases all scans, photos, measurements, and history from your device immediately and permanently. Because personal data only ever existed on your device, that single action is complete — there is nothing server-side to request deletion of.
Deleting the Proof Skincare app itself also removes this data. It is included in your iPhone’s own backups, so restoring a device or moving to a new iPhone keeps it, but deleting the app is permanent. A backup file you export yourself is under your control, in the location you chose to save it.
If this policy changes, the updated version will be posted at this address with a new date. Material changes to what data leaves your device would also be reflected in the app’s own disclosures.
Questions about privacy in Proof Skincare: stoqn780@gmail.com