Terms of Service — Stay at Zero

Last updated: 2026-08-14

Effective date: 2026-08-14

Operator: Paweł Graczyk

Product: Stay at Zero

1. Agreement

By using Stay at Zero (the “Service”), you agree to these Terms and our Privacy Policy. If you connect an account, you also agree that creating/using that account is subject to these Terms.

If you do not agree, do not use the Service.

2. The Service

Stay at Zero is a personal tool to track intermittent fasting sessions, view history and statistics, work offline on your device, and optionally sync with an account.

The Service is provided for personal, non-commercial use unless we agree otherwise in writing.

We may change, suspend, or discontinue features with reasonable notice where practicable.

3. Not medical advice

Stay at Zero is not a medical device and does not provide medical advice, diagnosis, or treatment.

Fasting can be inappropriate or unsafe for some people, including during pregnancy or breastfeeding, with eating disorders, diabetes, medications that require food, underweight, or other medical conditions. Consult a qualified clinician before longer or extended fasts, and before fasting if you have a health condition or take medication.

You are solely responsible for deciding whether fasting is suitable for you. Use the Service at your own risk.

In-app safety notes are informational only and are not a substitute for professional care.

4. Accounts and eligibility

You may use parts of the Service as a guest (device-local).
Connecting an account requires sign-in through our identity provider. You must keep your login credentials secure.
You must be at least 16 years old (or the age of digital consent in your country, if higher).
You are responsible for activity under your account.

We may refuse, suspend, or terminate access for abuse, security risk, or Terms violations.

5. Your content and data

You retain rights to the fasting data you enter. You grant us a limited license to host, process, and display that data as needed to operate the Service (including sync, backup import/export you initiate, and conflict handling).

You must not use the Service to store unlawful content or to attempt unauthorized access to other users’ data or our systems.

6. Acceptable use

You agree not to:

reverse engineer or disrupt the Service except as allowed by law
overload or abuse APIs (including circumventing rate limits)
impersonate others or misrepresent affiliation
use the Service in violation of applicable law

7. Intellectual property

The Service’s software, branding, and design are owned by us or our licensors. These Terms do not transfer ownership to you. You may not copy or redistribute the Service except as we expressly allow.

8. Availability and “as is”

The Service is provided “as is” and “as available.” We do not guarantee uninterrupted or error-free operation, perfect sync across devices, or that backups will always restore every record.

To the fullest extent permitted by law, we disclaim warranties of merchantability, fitness for a particular purpose, and non-infringement.

Consumer rights that cannot be waived under mandatory law remain unaffected.

9. Limitation of liability

To the fullest extent permitted by law, we are not liable for indirect, incidental, special, consequential, or punitive damages, or loss of data, profits, or goodwill, arising from your use of the Service.

Our aggregate liability for claims relating to the Service in any 12-month period is limited to the amount you paid us for the Service in that period (currently EUR 0).

Nothing in these Terms excludes liability that cannot be excluded under applicable law (including liability for death or personal injury caused by negligence where such exclusion is forbidden).

10. Deletion and export

You may export data and delete your Stay at Zero account using in-app controls when available, as described in the Privacy Policy.

Account deletion removes Stay at Zero server data for that account and then deletes the identity-provider user (self-delete). Clearing device data does not delete server data.

11. Third-party services

Sign-in and infrastructure providers are third parties with their own terms. We are not responsible for third-party services beyond our control.

12. Changes to these Terms

We may update these Terms. We will update the “Last updated” date. Material changes may be communicated in-app or by other reasonable means. Continued use after the effective date constitutes acceptance where permitted by law.

13. Governing law and disputes

These Terms are governed by the laws of Poland, without regard to conflict-of-law rules, except that mandatory consumer protections in your country of residence still apply.

Courts of Warsaw, Poland have jurisdiction, subject to mandatory consumer venue rules.

14. Contact

Questions about these Terms: support@stayatzero.com