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Terms of Service

Last updated: 5 June 2026 · Effective: 5 June 2026

1. Acceptance of these terms

By downloading, installing, or using CycleSync (the "App," "Service," or "we"), you agree to be bound by these Terms of Service ("Terms") and our Privacy Policy. If you do not agree, do not use the App. The App is operated by Tunnxo ("we," "us," "our").

2. About CycleSync

CycleSync is a mobile application that helps you log your menstrual cycle, visualize cycle phases, integrate with your device's calendar and (optionally) Apple Health or Google Health Connect, and receive reschedule suggestions for calendar events that conflict with your energy profile.

CycleSync is a wellness and productivity tool, not a medical device. See the health disclaimer below.

3. Accounts and eligibility

CycleSync does not require an account. You must be at least 13 years old to use the App. The App's store age rating (17+ on iOS, Everyone with medical content disclosure on Google Play) reflects the medical/health subject matter.

If you connect a calendar or health platform, you must have the legal right to grant CycleSync access. For example, only connect calendars you own or have authority to access.

4. License to use CycleSync

Subject to your compliance with these Terms, we grant you a limited, non-exclusive, non-transferable, revocable license to use CycleSync on devices you own or control, for personal, non-commercial purposes.

You may not:

• Resell, rent, lease, or sublicense the App.
• Reverse-engineer, decompile, or attempt to extract the source code of the App, except to the extent expressly permitted by applicable law.
• Modify, translate, or create derivative works of the App.
• Use the App to build a competing product or service.
• Remove or alter any proprietary notices or labels.

5. Your content

Cycle logs, calendar preferences, focus settings, and any other data you enter into CycleSync ("User Content") remain yours. Because the App is local-first and we do not operate servers that store User Content, you retain full control. We claim no ownership over your User Content.

You are responsible for the accuracy of the data you log. Inaccurate cycle logs may produce inaccurate phase predictions or suggestions.

6. Subscriptions & billing

Pricing

CycleSync Pro is offered as a weekly, monthly, or yearly subscription. Pricing is displayed in the App and on the relevant store page. Prices may vary by region and are subject to change with notice.

Billing

Subscriptions are billed through the Apple App Store or Google Play Store using the payment method linked to your store account. By starting a subscription, you authorize the store to charge your payment method on a recurring basis until you cancel.

Auto-renewal

Subscriptions automatically renew at the end of each billing period unless you cancel at least 24 hours before the end of the current period.

Canceling

You can cancel anytime in your store account settings:

• iOS: Settings → Apple ID → Subscriptions → CycleSync
• Android: Play Store → Profile → Payments & subscriptions → Subscriptions

You may also use the in-app Manage Subscription link on the Profile screen to be deep-linked to the appropriate store page.

Refunds

Refunds are governed by Apple's and Google's respective policies and are handled by the stores, not by us. CycleSync does not have access to your payment information and cannot issue refunds directly.

Free-tier changes

We may change the features included in the free tier with reasonable notice. Existing Pro subscribers retain the feature set available at the time of their subscription, subject to these Terms.

Price changes

If we increase the price of an existing subscription, we will notify you in advance. Continued subscription after the new price takes effect indicates acceptance of the new price. You may cancel before the new price takes effect to avoid being charged at the new rate.

7. Free tiers & trials

CycleSync offers a free tier with no time limit. The paywall appears after 8 days of use as a soft prompt — it does not block features already in use. We do not currently offer a paid trial; if we do in the future, the trial terms will be displayed in the App before any charge.

8. Acceptable use

You agree not to:

• Use CycleSync for any unlawful purpose or in violation of any applicable laws.
• Attempt to gain unauthorized access to the App's systems or related networks.
• Interfere with or disrupt the App or its security features.
• Use the App in any manner that could damage, disable, overburden, or impair our infrastructure (we have very little infrastructure, but the principle applies).
• Use CycleSync to harass, abuse, or harm another person.
• Use any automated means to access the App except as we explicitly permit.

9. Intellectual property

The App, including its design, code, graphics, illustrations, copy, and trademarks, is owned by Tunnxo and protected by copyright, trademark, and other intellectual-property laws.

"CycleSync," the CycleSync logo, and the four-season cycle metaphor as expressed in the App are our trademarks. You may not use them without our written permission, except as needed to refer to CycleSync (e.g., a press article).

10. Third-party services

The App relies on third-party platforms (Apple, Google, RevenueCat, Apple Health, Google Health Connect). Your use of those services is governed by their terms. We are not responsible for the availability or accuracy of third-party services. If a third-party service is unavailable, features that depend on it may be limited.

11. Health disclaimer

CycleSync is not a medical device and does not provide medical advice, diagnosis, or treatment. The cycle phases, energy predictions, and reschedule suggestions are general wellness and productivity tools, grounded in widely circulated ideas about menstrual cycle phases. They are not based on personalized medical assessment.

Always seek the advice of a qualified healthcare provider with any questions you may have regarding your health, menstrual cycle, fertility, or related matters. Never disregard professional medical advice or delay in seeking it because of something you have read or seen in CycleSync.

If you experience severe symptoms, sudden changes in cycle, or anything that concerns you, contact a licensed clinician. If you think you may have a medical emergency, call your local emergency number immediately.

12. Disclaimers & warranty

THE APP IS PROVIDED "AS IS" AND "AS AVAILABLE," WITHOUT WARRANTIES OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE, NON-INFRINGEMENT, AND ACCURACY OF PREDICTIONS.

We do not warrant that the App will be uninterrupted, error-free, or free of harmful components, or that the reschedule suggestions will always be optimal for your situation.

13. Limitation of liability

TO THE MAXIMUM EXTENT PERMITTED BY APPLICABLE LAW, IN NO EVENT SHALL TUNNXO, ITS AFFILIATES, OFFICERS, DIRECTORS, EMPLOYEES, OR AGENTS BE LIABLE FOR ANY INDIRECT, INCIDENTAL, SPECIAL, CONSEQUENTIAL, OR PUNITIVE DAMAGES, INCLUDING WITHOUT LIMITATION LOSS OF PROFITS, DATA, USE, GOODWILL, OR OTHER INTANGIBLE LOSSES, RESULTING FROM:

• YOUR ACCESS TO OR USE OF (OR INABILITY TO ACCESS OR USE) THE APP.
• ANY CONDUCT OR CONTENT OF ANY THIRD PARTY ON OR THROUGH THE APP.
• ANY DECISION YOU MAKE BASED ON THE APP'S SUGGESTIONS OR PREDICTIONS.
• UNAUTHORIZED ACCESS, USE, OR ALTERATION OF YOUR TRANSMISSIONS OR CONTENT.

IN ANY EVENT, OUR TOTAL CUMULATIVE LIABILITY TO YOU FOR ALL CLAIMS ARISING OUT OF OR RELATING TO THE USE OF, OR INABILITY TO USE, THE APP SHALL NOT EXCEED THE GREATER OF (A) THE AMOUNT YOU PAID US FOR THE APP IN THE 12 MONTHS PRECEDING THE CLAIM, OR (B) USD $50.

14. Indemnification

You agree to defend, indemnify, and hold harmless Tunnxo and its affiliates from and against any claims, liabilities, damages, losses, and expenses (including reasonable attorneys' fees) arising out of or in any way connected with your access to or use of the App, your violation of these Terms, or your violation of any third-party right.

15. Termination

These Terms remain in effect for as long as you use the App. We may suspend or terminate your access to the App at any time, with or without cause, with or without notice. Upon termination:

• The license granted in Section 4 ends.
• You must stop using the App and may uninstall it.
• Provisions that by their nature should survive (including ownership, disclaimers, indemnity, and limitations of liability) will survive.

Active Pro subscriptions are governed by the App Store / Play Store terms; termination of these Terms does not automatically cancel a paid subscription, but you can cancel the subscription separately.

16. Changes to these terms

We may update these Terms from time to time. When we do, we will revise the "Last updated" date at the top of this page. For material changes, we will surface a notice in the App on the next launch. Continued use of CycleSync after a material change indicates acceptance of the updated Terms. If you do not agree to the updated Terms, stop using the App and uninstall it.

17. Governing law & disputes

These Terms are governed by the laws of the jurisdiction in which Tunnxo is established, without regard to its conflict-of-law principles.

Informal resolution. We want to resolve any dispute without formal litigation. If you have a concern, please contact us first at legal@cyclesync.app and we'll try to resolve it informally within 30 days.

Mandatory arbitration (where permitted). If we can't resolve a dispute informally, and where permitted by applicable law, any dispute will be resolved by binding arbitration rather than in court, except that you may assert claims in small-claims court if your claims qualify. Nothing in this section prevents you from bringing a dispute to the attention of any consumer-protection agency.

Class-action waiver. To the extent permitted by applicable law, you and we agree that disputes will be brought only in an individual capacity and not as a class action or other representative action.

Exceptions. Either party may seek injunctive or equitable relief in court to prevent actual or threatened infringement of intellectual property.

Consumers in some jurisdictions (e.g., the EU, UK, California) may have additional rights that this section does not override.

18. Contact us

Questions about these Terms? Reach out at:

• Email: legal@cyclesync.app
• Support: cyclesync.app/support