Terms of service

1. Who we are and who you are

These terms are a contract between you and Circa Limited, a private company limited by shares incorporated in Hong Kong SAR. You means you, the individual using the Circa app or this website. By creating a Circa account, downloading the app, or using the service, you agree to these terms.

2. Eligibility

You may use Circa if you are at least 18, or 16 with a parent’s or guardian’s consent where local law requires it. Circa is rated 17+ and is not directed at children under 13.

3. What Circa is

Circa is a mobile application and supporting backend that produces a personalised plan to help you reduce jet lag around a flight, using established circadian-rhythm science. The plan considers your flight schedule, your chronotype, your habitual sleep, and (if you opt in) your physiological data from Apple HealthKit or a connected wearable.

4. Wellness guidance, not medical advice

Circa is a wellness and lifestyle product. It is not a medical device, it is not regulated as a medical device, and it does not diagnose, treat, cure, mitigate, or prevent any disease or condition. The recommendations Circa produces, including its sleep-shift schedule, light-exposure guidance, optional melatonin guidance, optional caffeine or alcohol guidance, and any score we may calculate, are general wellness suggestions. They are not a substitute for professional medical advice, diagnosis, or treatment.

Do not rely on Circa to address a sleep disorder, a circadian rhythm disorder, or any other medical condition. Always seek the advice of your physician or other qualified healthcare provider with any questions you may have regarding a medical condition. If you think you may have a medical emergency, call your doctor or local emergency services immediately.

5. Subscriptions and payment

Some Circa features require a paid subscription, sold as an in-app purchase through Apple’s App Store. Subscriptions auto-renew at the end of each billing period unless you cancel at least 24 hours before the period ends. You can manage and cancel your subscription in the App Store on your device.

Refunds are handled by Apple. Most regions allow refund requests within Apple’s standard window. The first plan is free.

6. Your account

Keep your account secure. You are responsible for activity under your account. Notify us if you suspect unauthorised access by emailing hello@circa-app.io.

7. Acceptable use

Use Circa only for its intended purpose. Do not attempt to reverse-engineer the engine, scrape the service, or use it in a way that interferes with other users.

8. Intellectual property

The Circa app, website, brand, and engine are owned by Circa Limited. The Circa name and logo are trademarks. Your trip data is yours; you grant us a limited licence to process it to operate the service.

9. Affiliate links and recommendations

Some links from the app or website may be affiliate links. We may earn commission on certain physical product purchases. The plan’s recommendation set is independent of commission rates. See the affiliate program page for details.

10. Limitation of liability

To the maximum extent permitted by law, Circa Limited is not liable for indirect, incidental, special, or consequential damages arising from your use of the service. Some jurisdictions do not allow these limitations; in those jurisdictions, our liability is limited to the maximum extent permitted.

11. Termination

You may delete your account at any time from within the app. We may suspend or terminate your account if you breach these terms.

12. Governing law

These terms are governed by the laws of Hong Kong SAR. Disputes are subject to the non-exclusive jurisdiction of the Hong Kong courts.

13. Changes

If we change these terms materially, we will tell you in-app or by email before the change takes effect.

14. Contact

Email hello@circa-app.io.