Terms of Use for the SAYA App

Note: This English version is provided for convenience. The German version is legally binding.

These Terms of Use govern your use of the SAYA app. Use of the website saya-sleep.com and the waitlist is covered by separate terms. How we handle your data is described in the App Privacy Policy.

Provider: Lukas Bröll, Bodmanstr. 23, 87439 Kempten, Germany — Email: l.broell@freenet.de

1. Scope and acceptance

These terms form an agreement between you and the provider named above. You accept them when you create a SAYA account. We may update them; you will be notified in the app of material changes, and continued use after such notice constitutes acceptance.

2. What SAYA is — and what it is not

SAYA reads data from your Garmin wearable and your own entries and computes scores, patterns and correlations relating to your sleep and overnight recovery.

SAYA is a wellness product, not a medical device. It does not diagnose, treat, cure or prevent any disease, and it is not a substitute for professional medical advice. Its outputs are estimates derived from consumer wearable data, not clinical measurements.

Do not use SAYA to make medical decisions. If you suspect a sleep disorder or any other condition, or before making significant changes to your sleep, training or diet, consult a qualified health professional. In an emergency, contact emergency services.

3. Eligibility

You must be at least 16 years old to use SAYA. By creating an account you confirm that you are.

4. Your account

You are responsible for keeping your login credentials confidential and for activity under your account. Provide accurate information — personal details such as date of birth and gender feed directly into the calculations, and inaccurate entries produce inaccurate results.

One account is for one person. Do not share an account.

5. Garmin connection

SAYA requires a Garmin account and a compatible Garmin device. You authorise the transfer of data from Garmin to SAYA in your Garmin account, and separately consent in the app to our processing of that health data.

Garmin is an independent company. We do not control the availability, accuracy or continuation of the Garmin API, and interruptions on Garmin's side may limit or stop SAYA's functionality. Garmin™ is a trademark of Garmin Ltd. or its subsidiaries; SAYA is not affiliated with, endorsed or sponsored by Garmin.

You may disconnect Garmin at any time in the app. You will then be asked whether the data already imported should be kept or deleted.

6. Beta / early access

Parts of SAYA may be provided as a beta or early-access version. Beta versions may contain errors, may be incomplete, may compute incorrect values and may be changed or discontinued at any time. They are provided as-is and without any warranty as to fitness for a particular purpose.

7. Availability

We aim to keep SAYA available but do not guarantee uninterrupted operation. Maintenance, updates, faults or failures of third-party services (Garmin, Google Cloud) may cause downtime. We may change, add to or discontinue features.

8. Subscriptions and payment

Basic functions are free of charge. Paid subscriptions ("SAYA Premium") may be offered.

  • Purchases are made exclusively through the Apple App Store or Google Play. Your contracting party for the purchase is Apple or Google, not us, and their terms apply to the transaction.
  • Price, term and features are shown before purchase.
  • Subscriptions renew automatically at the end of each term unless cancelled at least 24 hours before it ends.
  • Cancellation and refunds are handled in your Apple or Google account, under their respective rules. We cannot issue refunds for store purchases ourselves.
  • If a subscription ends, paid features become unavailable. Your data remains stored while your account exists.

9. Acceptable use

You may not: reverse engineer, decompile or modify the app except where the law permits; access it by automated means or place unreasonable load on our systems; circumvent access controls or use the app for anyone other than yourself; or resell or commercially exploit the app or its outputs.

10. Intellectual property

The app, its design, its texts and the algorithms behind the scores are ours and are protected by law. You receive a personal, non-transferable, revocable right to use the app for its intended purpose. Your own data remains yours; you can export it at any time in the app.

11. Liability

We are liable without limitation for intent and gross negligence, for injury to life, body or health, and under the German Product Liability Act.

In cases of slight negligence, we are liable only for breach of essential contractual obligations (obligations whose fulfilment makes proper performance possible in the first place and on whose observance you may regularly rely), and in that case limited to the foreseeable damage typical for this type of contract.

We are not liable for decisions you make on the basis of the app's outputs, for the accuracy of data supplied by Garmin, or for outages of third-party services.

12. Term and termination

The agreement runs for as long as your account exists. You may delete your account at any time in the app (Settings → Delete account); this ends the agreement and erases your data as described in the Privacy Policy.

We may terminate or suspend your account for serious or repeated breaches of these terms, or if we discontinue SAYA. In the latter case we will give you reasonable notice and an opportunity to export your data.

Accounts left unused for 24 months are deleted, after a warning by email 30 days beforehand.

13. Final provisions

Applicable law: the law of the Federal Republic of Germany. For consumers, this choice applies only to the extent that it does not deprive you of the protection of mandatory provisions of the law of your country of habitual residence.

Jurisdiction: if you are a merchant, a legal entity under public law or a special fund under public law, the place of jurisdiction is Kempten (Allgäu), Germany. For consumers, the statutory places of jurisdiction apply.

Consumer dispute resolution: we are neither willing nor obliged to participate in dispute resolution proceedings before a consumer arbitration board (Section 36 VSBG).

Severability: if any provision is or becomes invalid, the remaining provisions are unaffected.

Last updated: September 2026