Terms of Use

1. This agreement

These Terms of Use (the "Terms") are a legal agreement between you and Gleb Matsko, an individual developer based in Serbia ("we", "us"), the developer of the Scalin mobile application for iPhone and Apple Watch (the "App").

By downloading, installing or using the App you accept these Terms. If you do not accept them, do not use the App and delete it from your devices.

This agreement is between you and us alone, not with Apple Inc. ("Apple"). Apple is not responsible for the App or its content.

2. Your licence

We grant you a personal, non-exclusive, non-transferable, revocable licence to use the App on Apple-branded devices that you own or control, as permitted by the Usage Rules of the Apple Media Services Terms and Conditions. Where Apple's Family Sharing or volume purchasing applies, the App may be accessed by other accounts associated with you as those rules allow.

You may not: copy, modify, translate or create derivative works of the App; reverse engineer, decompile or disassemble it except to the extent that applicable law expressly permits this despite this restriction; rent, lease, lend, sell, sublicense or redistribute it; or remove any proprietary notices.

3. Scalin Pro subscriptions

The App is free to download. It includes an auto-renewing subscription, Scalin Pro, which unlocks the trend line, the weekly rate, forecasts, the character and the widgets. Without Pro the App continues to work: your log and the raw chart remain available.

Prices are shown in US dollars and may differ in your local storefront; the price you pay is the one shown on the purchase screen at the moment of confirmation, including any applicable taxes.

Free trial. Where offered, a 7-day free trial is available once per Apple Account. If you already used a trial or introductory offer for Scalin, the subscription starts as a paid period. Any unused portion of a free trial is forfeited when you buy a subscription.

Billing and renewal. Payment is charged to your Apple Account at confirmation of purchase. The subscription renews automatically at the same price and period unless it is cancelled at least 24 hours before the end of the current period. Your account is charged for renewal within 24 hours before the end of the current period.

Cancellation. Manage and cancel your subscription in Settings → your name → Subscriptions on your device. Deleting the App does not cancel a subscription. Cancelling stops the next renewal; you keep Pro until the end of the period you already paid for.

Refunds are handled by Apple. See our Refund Policy.

We may change prices or the contents of a plan for future periods. Where the law requires it, we will notify you in advance and give you the chance to cancel before the change takes effect.

4. Not medical advice

Scalin is a tracking tool, not a medical device. It does not diagnose, treat, cure or prevent any disease or condition, and it is not intended for use in making medical decisions.

The "true weight" line is an exponentially weighted moving average (α 0.1) of the weigh-ins you enter yourself — the method described in The Hacker's Diet. It is a smoothing of your own measurements. It is not a measurement in its own right, not a clinical assessment and not a prediction. Forecasts are arithmetic extrapolations of past data shown as a range, and the future is under no obligation to match them.

The App does not ask for your height, does not calculate a BMI and does not tell you what to eat or how to exercise. Always consult a qualified healthcare professional about your weight, your health and any decision that concerns them. If you have or suspect an eating disorder, please seek professional support; daily weighing is not appropriate for everyone.

5. The character

The App shows one humorous line per day, selected by the context of your recent weigh-ins, in a tone you choose (Supportive, Snarky or Merciless) and can change at any time in Settings. The lines are jokes about scales, salt, water retention and weekdays. They are not advice, not an assessment of you, and not a statement of fact. If a line does not land, mute it and it will not appear again.

6. Your use of the App

You are responsible for the accuracy of the data you enter and for keeping your device and your Apple Account secure. You agree not to use the App unlawfully, not to interfere with its operation or security, and not to use it to build a competing product.

Scalin has no user accounts, no user-generated content shared with others and no social features. Nothing you enter is transmitted to us.

7. Intellectual property

The App, its source code, design, the mascot, its written content and all related trademarks are owned by us or our licensors and are protected by copyright and other laws. These Terms grant you a licence to use the App, not any ownership of it. The bundled Nunito typeface is used under the SIL Open Font License.

8. Privacy and health data

Your weigh-ins are stored on your device and, if you keep iCloud enabled, in your own iCloud account — we have no server that receives them. Health data read from or written to Apple Health stays on your device, is used only to show you your own trend, and is never used for advertising, sold, or sent to any third party including our analytics provider.

The App does collect anonymous usage and crash data about the App itself (screens opened, features used, device model, app version, crashes) through Google Analytics for Firebase, so that we can maintain and improve it. That data carries no weight, no weigh-in and no health data, and you can switch it off in the App's settings. The Privacy Policy sets out exactly what is collected and how to opt out.

9. Availability and changes

We may update, change or discontinue the App or any of its features. We aim to keep Pro features working for any period you have paid for; if we discontinue the App entirely, we will stop selling new subscriptions and let existing ones lapse rather than cutting them short.

The App requires a compatible Apple device and a supported version of iOS or watchOS. Some features depend on services we do not control (Apple Health, iCloud, the App Store) and may stop working if those change.

10. Disclaimer of warranties

To the maximum extent permitted by applicable law, the App is provided "as is" and "as available", without warranties of any kind, whether express, implied or statutory, including any implied warranties of merchantability, fitness for a particular purpose, accuracy and non-infringement. We do not warrant that the App will be uninterrupted, error-free, or that any calculation, trend or forecast will be accurate or complete.

Some jurisdictions do not allow the exclusion of implied warranties, so parts of this section may not apply to you. Nothing here limits any statutory rights you have as a consumer.

11. Limitation of liability

To the maximum extent permitted by applicable law, we are not liable for any indirect, incidental, special, consequential or punitive damages, or for loss of data, arising out of or connected to your use of the App. Our total liability for any claim relating to the App is limited to the amount you paid us for it in the twelve months before the event giving rise to the claim.

Nothing in these Terms excludes or limits liability for death or personal injury caused by negligence, for fraud, or for anything else that cannot lawfully be excluded.

12. Apple-specific terms

The following apply because you obtained the App from the App Store:

• Responsibility. These Terms are between you and us only. We, not Apple, are solely responsible for the App and its content.
• Maintenance and support. We are solely responsible for any maintenance and support for the App. Apple has no obligation to furnish any maintenance or support services.
• Warranty. In the event of any failure of the App to conform to any applicable warranty, you may notify Apple and Apple will refund the purchase price for the App (if any) to you. To the maximum extent permitted by law, Apple has no other warranty obligation whatsoever with respect to the App.
• Product claims. We, not Apple, are responsible for addressing any claims relating to the App, including product liability claims, any claim that the App fails to conform to a legal or regulatory requirement, and claims arising under consumer protection or similar legislation.
• Intellectual property claims. In the event of any third-party claim that the App infringes that party's intellectual property rights, we, not Apple, will be responsible for the investigation, defence, settlement and discharge of that claim.
• Legal compliance. You represent that you are not located in a country subject to a U.S. Government embargo or designated as "terrorist supporting", and that you are not on any U.S. Government list of prohibited or restricted parties.
• Third-party beneficiary. Apple and its subsidiaries are third-party beneficiaries of these Terms and, upon your acceptance, will have the right to enforce them against you.

13. Termination

These Terms apply until terminated. They end automatically if you stop using and delete the App. We may terminate them if you materially breach them. On termination your licence ends; sections 7, 10, 11, 12 and 14 survive.

14. Governing law

These Terms are governed by the laws of the Republic of Serbia, without regard to its conflict-of-laws rules. If you are a consumer resident in the European Union, the United Kingdom or another jurisdiction with mandatory consumer protection rules, you keep the benefit of the protections of your country of residence and may bring proceedings there.

15. Changes to these Terms

We may update these Terms. The current version is always at scalinapp.com/terms with the date at the top. Material changes will be notified in the App or on this page before they take effect. Continuing to use the App after that means you accept the updated Terms.

16. Contact

Gleb Matsko, Serbia
Email: support@scalinapp.com

Apple's standard licence terms, which apply where these Terms are silent, are published at apple.com/legal/internet-services/itunes/dev/stdeula.