Privacy Policy

Last updated: June 19, 2026

This Privacy Policy explains what information Calorie Puzzle ("the App," "we," "us"), operated by Stellandra, collects, how we use it, and the choices you have. By using the App you agree to this policy.

Information We Collect

We collect only what the App needs to work. You can start using the App as an anonymous account, in which case we do not collect your email or name.

Account information: your email address and display name, and — if you sign in with Apple or Google — the identifier returned by that provider. Anonymous accounts have none of these until you choose to register or upgrade.
Health & nutrition data: your meal logs (food name, calories, protein, carbs, fat, fiber, sugar, sodium, meal type, serving size, date) — including any corrections you make to an AI estimate, which we use to improve future estimates for you — your weight records, and your body profile and goals (gender, date of birth, height, activity level, goal, target weight). You enter this yourself; it is not synced from Apple Health or any other health service.
Food photos: when you scan a meal, the photo is sent for real-time AI analysis. We do not store your photos — see "How Your Food Photos Are Handled" below.
Usage counters: the number of AI scans you make per day, used to enforce the free-tier limit and your subscription entitlement.
Subscription status: whether you have an active subscription, managed through RevenueCat and the App Store.
Anonymous device identifier: a random identifier we generate on your device (not your hardware ID, not an advertising ID) used solely for anti-abuse — see "Anonymous Accounts and Device Identifier" below.
Technical settings: your time zone (to calculate your daily totals correctly), language, and unit preference.

How We Use Your Information

To provide AI-powered food recognition and nutrition estimation.
To track your daily nutrition, weight trends, and generate your reports, streaks, and badges.
To calculate your calorie and macro targets from your profile.
To manage your account, sign-in, and subscription.
To enforce free-tier limits and prevent abuse of our AI services.
To send you a password-reset email if you request one.
With your permission, to send you meal-reminder notifications. These are scheduled locally on your device; you can turn them off at any time in your device settings.

We do not show ads in the App, and we do not use advertising identifiers or cross-app tracking. We do not ask for App Tracking Transparency permission for advertising.

How Your Food Photos Are Handled

When you scan a meal, your photo is sent to Google (Gemini AI) for real-time analysis to identify the food and estimate its nutrition. The image itself is processed in the moment and is not stored by us — we never save your photos to our servers or any file storage. To keep AI costs down, our server keeps a one-way fingerprint (a SHA-256 hash) of the image together with the nutrition result for up to 30 days; this fingerprint cannot be turned back into your photo and is not linked to your account. Only the nutrition values you choose to save are kept with your meal log.

Third-Party Services

We share data only with the service providers that make the App function. We do not sell your data, and we do not share it for advertising.

Google (Gemini AI): receives your meal photo (for the moment of analysis) and food-name text you ask us to estimate, to identify foods and estimate nutrition. No account identity is sent with it.
Google Firebase Authentication: verifies your sign-in when you use Sign in with Apple or Sign in with Google.
RevenueCat: manages subscription billing and verifies purchases. It uses an anonymous app-user identifier; we do not pass it your email or health data.
Apple App Store: processes in-app purchases for subscriptions.
Resend: delivers transactional email — used only to send a password-reset link when you request one.
Railway: hosts our backend and database, acting as a processor on our behalf.

Anonymous Accounts and Device Identifier

You can use Calorie Puzzle without creating an account. When you do, the App generates a random device identifier (a version-4 UUID) and stores it securely on your device. Its only purpose is anti-abuse: to recognize one anonymous account per device so the free AI-scan quota cannot be farmed by repeatedly creating new anonymous accounts. This identifier is not an advertising identifier, is not used for tracking across apps, and is not shared with any third party. When you upgrade an anonymous account to a full account (or merge it via Apple/Google sign-in), this device identifier is cleared.

Data Storage & Security

Your account and nutrition data are stored on our backend database (hosted on Railway). Passwords are never stored in plain text — they are protected using bcrypt hashing. Connections to our servers use encryption in transit (HTTPS). Your authentication tokens are kept in your device's secure storage. We retain your data while your account is active and remove or de-identify it as described below when you delete your account.

Your Rights and Choices

Access: view your data any time inside the App.
Correct: edit your profile, meals, and weight records in the App.
Delete: delete your account at any time via Profile › Delete Account (see below).

Account Deletion & Data Retention

When you delete your account, we permanently remove your personal information that can identify you — your email address, display name, password, and your Apple/Google sign-in identifiers — and your account is deactivated so it can no longer be used to sign in. Because we do not store your food photos, there are none to delete.

To keep our nutrition data accurate over time, your de-identified numeric records (such as meal nutrition values, weight entries, profile metrics, and the corrections you made to AI estimates) may be retained after deletion, but they are no longer linked to your identity once your personal information has been removed. If you would like assistance with deletion, contact us at support@stellandra.com.

We Do Not Sell Your Data

We do not sell or rent your personal information to anyone, and we do not share it with advertisers.

Children's Privacy

Calorie Puzzle is a general wellness app rated for ages 4+ and is not directed to children. We do not knowingly collect personal information from children under the age required by your local law. If you believe a child has provided us personal information, contact us and we will remove it.

Changes to This Policy

We may update this Privacy Policy from time to time. We will revise the "Last updated" date above, and your continued use of the App after changes take effect constitutes acceptance of the updated policy.

Contact Us

If you have questions about this Privacy Policy, contact us at support@stellandra.com.