Legal · Terms

Terms of Service

App: Callyx Effective: 2026-09-06 Last Updated: 2026-09-06

These Terms of Service ("Terms") govern your use of the Callyx mobile application ("the App"), operated by Tranquil Mind Technology JSC ("we", "us", "our"). By downloading or using the App, you agree to these Terms and to our Privacy Policy (https://policy.tranquilmind.co/callyx/privacy). If you do not agree, do not use the App.

1. Eligibility

You must be at least 13 years old (or the higher age of digital consent in your country) to use the App. By using Callyx you confirm that you meet this requirement.

2. License

We grant you a personal, limited, non-exclusive, non-transferable, revocable licence to install and use the App on devices you own or control, for your own non-commercial use. You may not copy, modify, distribute, sell, rent, sub-licence, reverse-engineer, decompile, or create derivative works from the App, except to the extent that applicable law expressly permits it.

3. The service

Callyx identifies incoming callers, blocks or silences calls from numbers you place on your block or spam list, lets you browse and dial your contacts, and keeps a local log of message notifications so you can read messages that a sender later deletes or recalls.

How the features depend on Android permissions and roles.

Caller ID and Contacts require the Contacts permission. Callyx reads your address book on your device only.
Call blocking and spam silencing work through Android's CallScreeningService and only take effect once you set Callyx as your device's default caller-ID & spam app. Until you do, Callyx cannot block or silence any call.
The recalled/deleted message log works through Android Notification Access, which you must grant explicitly in Android Settings. Callyx only records notifications your messaging apps post while the permission is active; it cannot recover messages sent before you granted it, and it cannot recover a message that never produced a notification (for example because the app was muted, the phone was off, or the sender deleted it before it was delivered).

No guarantee of blocking or identification. Caller identification and spam blocking depend on your contacts, the lists you maintain, your carrier, your device manufacturer's dialer, and Android platform behaviour. We do not warrant that every unwanted call will be blocked, that every caller will be identified correctly, or that no legitimate call will ever be silenced. Do not rely on Callyx for emergency communications. Callyx never blocks emergency services, and you remain responsible for calls you choose to block.

Lawful use of the message log. The recalled-message feature records notifications delivered to your device for your own reference. You are responsible for using it lawfully. Do not install Callyx on a device belonging to another person in order to monitor their messages without their knowledge and consent, and do not use the App in any way that breaches privacy, interception, or surveillance laws where you live. Callyx is not a monitoring, stalkerware, or parental-surveillance product and must not be used as one.

Availability may vary by region and by Android version, and we may modify, suspend, or discontinue the App or any of its features at any time.

4. Price and advertising

The App is free to download and use. There are currently no subscriptions and no in-app purchases; the App does not process any payment. Callyx is supported by advertising (app-open, banner, interstitial, and native ads) provided by Google AdMob and its mediation partners. Where required by law, an ad-consent form is presented on first launch and your choice can be changed at any time from the App's Settings screen. If paid features are introduced in the future, their pricing and billing terms will be presented to you in the App before you are charged, and these Terms will be updated.

5. Acceptable use

You agree not to: use the App for any unlawful purpose; use it to intercept, monitor, or record another person's communications without their consent; interfere with or disrupt the App or its supporting infrastructure; bypass, block, or tamper with advertising, access controls, or security measures; use bots, scrapers, or automated means to interact with the App; or infringe our rights or those of any third party. We may suspend or terminate your access for any violation.

6. Intellectual property

The App, its design, source code, trademarks, logos, and content are owned by Tranquil Mind Technology JSC or its licensors and are protected by intellectual-property laws. Names of third-party messaging applications (for example WhatsApp, Messenger, Instagram, Telegram) and their marks belong to their respective owners; their appearance in the App is for identification of the source of a notification only and does not imply affiliation, sponsorship, or endorsement.

7. Third-party services and content

The App uses third-party services for advertising, attribution, analytics, and crash reporting, and it interacts with Android system services provided by your device manufacturer and carrier. Each is governed by its own terms and privacy policy, and we are not responsible for them or for any third-party content shown through them.

8. Disclaimers

The App is provided "as is" and "as available", without warranties of any kind, express or implied, including merchantability, fitness for a particular purpose, and non-infringement. We do not warrant that the App will be uninterrupted, timely, error-free, or secure, that caller identification will be accurate, or that unwanted calls will always be blocked. The App is not a security, emergency, or legal service and does not provide professional advice.

9. Limitation of liability

To the maximum extent permitted by law, we are not liable for any indirect, incidental, special, consequential, or punitive damages, or for any loss of data, missed calls, missed messages, or lost business or profits, arising from your use of or inability to use the App. Our total aggregate liability is limited to the greater of the amounts you paid us for the App in the twelve months before the claim or USD 50. Some jurisdictions do not allow certain exclusions or limitations, so parts of this section may not apply to you.

10. Indemnification

You agree to indemnify and hold harmless Tranquil Mind Technology JSC, its officers, employees, and partners from any claim, loss, liability, or expense (including reasonable legal fees) arising out of your misuse of the App, your unlawful use of the message log or call-blocking features, or your breach of these Terms.

11. Termination

We may suspend or terminate your access to the App at any time, including for breach of these Terms. You may end these Terms at any time by uninstalling the App. Sections 6, 8, 9, 10, and 13 survive termination.

12. Changes to these Terms

We may update these Terms from time to time. Material changes will be posted on this page with a new "Last updated" date. Continued use of the App after an update means you accept the revised Terms.

13. Governing law and disputes

These Terms are governed by the laws of Vietnam, without regard to conflict-of-laws rules. The courts of Hanoi, Vietnam have jurisdiction over any dispute. Mandatory consumer-protection rights available to you under the law of your country of residence are not affected.

14. Contact

Tranquil Mind Technology JSC No. 3, Alley 98, Vu Trong Phung Street, Thanh Xuan Ward, Hanoi City, Vietnam Email: contact@tranquilmind.co