ScalinIn short: your weight never leaves your device. Weigh-ins are stored locally and sync only through your own iCloud — we have no server that could receive them, and Apple Health data is never transmitted anywhere. What we do collect is anonymous usage and crash data about the app itself, through Google Analytics for Firebase, so we know which screens people use and what breaks. That stream contains no weight and no health data.
1. Who we are
Scalin is developed by Gleb Matsko, an individual developer based in Serbia ("we", "us"), the data controller for the processing described below. Contact: support@scalinapp.com.
2. What is collected, and what is not
| Data | Leaves your device? |
|---|---|
| Your weigh-ins, trend, goals, streak | No — device only, plus your own iCloud if enabled |
| Apple Health data (body mass) | No — device only |
| Your height, BMI, calories, diet | Never asked for. The app does not have them |
| Name, email, phone, account | Never asked for. There are no accounts |
| App usage events, device model, OS and app version, approximate country, crash reports | Yes — to Google Analytics for Firebase, pseudonymously |
| Payment details | Handled by Apple. We never see them |
3. What stays on your device
Your weigh-ins (weight, date, time), goals, unit preference, chosen tone, muted lines and reminder time are stored in the app's container on your device. A copy is written to Apple's key-value store so that your iPhone and Apple Watch stay in step — that copy lives in your iCloud account, under your Apple Account, not ours. We have no access to it, and it is governed by Apple's privacy policy and iCloud terms. Turn iCloud off for Scalin and the app keeps working with local data only.
4. Apple Health (HealthKit)
With your explicit permission, Scalin reads body-mass samples from Apple Health and writes your weigh-ins back to it, so your history is on the chart from day one and smart scales that already sync to Health appear in Scalin on their own.
- Health data is used only to show you your own weight, trend and progress inside the app.
- Health data is never sent to us, to Google, to Firebase, to any analytics service or to any other third party.
- Health data is never used for advertising, marketing or use-based data mining beyond your own experience in the app.
- Health data is never sold or disclosed to data brokers or information resellers.
Granting Health access is optional — "start from today" during onboarding skips it entirely. You can withdraw it at any time in Settings → Privacy & Security → Health → Scalin.
5. Usage analytics and crash reporting
Scalin uses Google Analytics for Firebase (and Firebase Crashlytics) to understand how the app is used and to find bugs. Google acts as our processor for this data.
What is sent:
- A randomly generated app instance identifier, which identifies an installation, not a person;
- Device model, operating system version, app version, device language and screen size;
- Approximate location — country or region, derived from the IP address of the connection;
- Events describing use of the app: sessions, screens opened, features used, subscription screen shown, onboarding completed, and similar;
- Crash and diagnostic reports: the state of the app when it failed, including a stack trace.
What is never sent: your weight, any individual weigh-in, your trend, your goals, your Apple Health data, your name, your email address or your precise location. Nothing that could reveal what you weigh is included in an analytics event, by design and because Apple's rules forbid it.
Scalin does not use the Advertising Identifier (IDFA), shows no App Tracking Transparency prompt, and does not track you across other companies' apps or websites. There is no advertising network in the app.
How to turn it off: analytics can be disabled in the app under Settings → Privacy → Share usage data. Turning it off stops collection on that device from that moment on. You may also object at any time by writing to support@scalinapp.com.
Google's own handling of this data is described at firebase.google.com/support/privacy and policies.google.com/privacy.
6. Purchases
Subscriptions are sold by Apple, not by us. Apple processes the payment and holds the payment details; we never see your card, your billing address or your Apple Account email. Apple provides us with aggregated, non-identifying sales and subscription reports (units, revenue, country, retention) that cannot be traced back to a person.
7. Notifications
If you allow them, Scalin sends one type of local notification: the morning reminder to weigh yourself. It is scheduled on your device and never sent from a server. There are no marketing notifications, ever. Turn them off in the app's settings or in iOS Settings.
8. Legal bases (EEA and UK)
| Purpose | Basis |
|---|---|
| Running the app; storing your weigh-ins on your device | Performance of a contract, Art. 6(1)(b) GDPR |
| Reading and writing Apple Health data | Your explicit consent, Art. 9(2)(a) — withdrawable in iOS Settings |
| Usage analytics and crash reporting | Our legitimate interest in maintaining and improving the app, Art. 6(1)(f) — you may object, or switch it off in the app |
| Complying with tax, accounting and legal obligations | Art. 6(1)(c) |
9. Retention
Data on your device stays until you delete the entry, the app or its iCloud data. Analytics events are retained by Google on our behalf for no longer than 14 months from collection, and crash reports for no longer than 90 days, after which they are deleted or aggregated.
10. International transfers
Your weigh-ins and health data do not leave your device, so no transfer arises for them. Analytics and crash data are processed by Google LLC and its affiliates, including in the United States. Those transfers rely on the European Commission's Standard Contractual Clauses and, where applicable, the EU–US Data Privacy Framework, as set out in Google's data processing terms.
11. Your rights
You have the right to access, correct, erase, restrict and object to the processing of your personal data, and to data portability. In practice:
- Your weight data is already entirely in your hands: view and edit it in the app, export it through Apple Health, delete an entry in the app, or delete the app and its iCloud data to erase all of it.
- Analytics data: switch it off in the app, or email us. To have data already collected for your installation deleted, send us the app instance identifier shown in Settings → Privacy — it is the only way to identify your installation, since we hold nothing else about you.
- You may lodge a complaint with your local supervisory authority.
California residents: we do not sell or share personal information as those terms are defined by the CCPA/CPRA, and we do not use it for cross-context behavioural advertising. The categories collected are identifiers (a pseudonymous app instance ID), internet or network activity (in-app usage) and coarse geolocation (country).
12. Security
Your data is protected by the device encryption iOS and watchOS provide, and you can add a Face ID / Touch ID lock to the app in Settings. Analytics data is sent to Google over TLS. Because your weigh-ins are never transmitted to us, there is no server-side database of your health data that could be breached.
13. Children
Scalin is not directed at children under 13 (or the equivalent minimum age in your country) and we do not knowingly process their data. The app is rated for teens and older because of its humour.
14. Third parties
The only third parties involved are Apple (App Store purchases, iCloud sync, Apple Health — all under Apple's privacy policy) and Google (Analytics for Firebase and Crashlytics, as our processor). There is no advertising network, no attribution SDK and no data broker in the app.
15. This website
scalinapp.com is a static site. It sets no cookies and runs no analytics. It loads one external resource — the Nunito webfont from Google Fonts — which receives your IP address in order to serve the font file.
16. Changes to this policy
The current version is always at scalinapp.com/privacy with the date at the top. If a future version of Scalin processes anything materially differently, this page will be updated before that version ships, and where the law requires consent, the app will ask for it first.
17. Contact
Gleb Matsko, Serbia
Email: support@scalinapp.com