Terms of Service

Last updated: July 23, 2026

These Terms of Service (“Terms”) govern your use of the Tongue mobile application (“Tongue,” the “app”) operated by 4DHD, Inc. (“we,” “us,” “our”). By downloading or using the app, you agree to these Terms. If you do not agree, do not use the app.

Important — not medical advice.

Tongue is a wellness and self-reflection tool inspired by traditional tongue observation. It does not provide medical advice, diagnosis, or treatment, and its readings are for general informational and educational purposes only. Tongue is not a medical device and is not a substitute for professional medical care. Always seek the advice of a qualified health provider with any questions about a medical condition, and never disregard or delay professional advice because of something the app showed you. If you think you may have a medical emergency, call your doctor or emergency services immediately.

1. Who can use Tongue

You must be at least 18 years old, or the age of majority in your jurisdiction, to use Tongue. By using the app you represent that you meet this requirement. Tongue is not intended for children.

2. Your account and identity

Tongue does not require you to create an account or provide personal details. Your journal is associated with a random identifier stored on your device. You are responsible for the device you use and for any activity that occurs through it. See our Privacy Policy for how this works.

3. Your content

You retain ownership of the photos, notes, and tags you add (“Your Content”). You grant us a limited license to store, process, and display Your Content solely to operate the app and provide its features to you — including uploading photos to our storage and sending them to our analysis provider to generate your reading. We do not use Your Content for advertising, and we do not sell it.

4. Acceptable use

You agree not to: (a) use the app for any unlawful purpose; (b) upload content that is not your own tongue photo or that infringes the rights of others; (c) attempt to disrupt, reverse-engineer, or gain unauthorized access to the app or its systems; or (d) misuse the analysis for the diagnosis or treatment of any person.

5. Subscriptions, billing, and free trials

Tongue offers a free first reading. Continued and unlimited use of certain features requires Tongue Pro, an auto-renewing subscription. The following terms apply to subscriptions purchased through the Apple App Store or Google Play:

Subscriptions are offered on a monthly or annual basis and are billed through your Apple or Google account at the price shown in the app at the time of purchase.
Your subscription automatically renews at the end of each period unless you cancel it at least 24 hours before the period ends. Your account is charged for renewal within 24 hours before the end of the current period.
If a free trial is offered, any unused portion is forfeited when you purchase a subscription. Unless you cancel at least 24 hours before the trial ends, the trial automatically converts to a paid subscription.
You can manage or cancel your subscription in your App Store or Google Play account settings after purchase.
Payments are processed by Apple or Google, not by us. Except where required by law or the applicable store’s policy, payments are non-refundable; refund requests are handled by the store.

6. Changes to the app and pricing

We may add, change, or discontinue features at any time. If we change subscription pricing, the change will not affect your current billing period, and continued use after a price change that takes effect on renewal requires your consent through the app store as applicable.

7. Intellectual property

The app, including its software, design, text, and branding (excluding Your Content), is owned by 4DHD, Inc. and protected by intellectual property laws. We grant you a limited, non-exclusive, non-transferable, revocable license to use the app for your personal, non-commercial use in accordance with these Terms.

8. Disclaimer of warranties

The app and all readings are provided “as is” and “as available,” without warranties of any kind, whether express or implied, including warranties of merchantability, fitness for a particular purpose, accuracy, and non-infringement. We do not warrant that readings are accurate, reliable, or complete, or that the app will be uninterrupted or error-free. Any reliance on the app’s output is at your own risk.

9. Limitation of liability

To the maximum extent permitted by law, 4DHD, Inc. and its officers, employees, and providers will not be liable for any indirect, incidental, special, consequential, or punitive damages, or for any loss of data, arising out of or relating to your use of (or inability to use) the app. To the extent liability cannot be excluded, our total liability for any claim relating to the app will not exceed the greater of the amount you paid us in the twelve months before the claim or USD $50.

10. Indemnification

You agree to indemnify and hold harmless 4DHD, Inc. from any claims, damages, or expenses arising out of your misuse of the app or your violation of these Terms.

11. Termination

You may stop using the app at any time. We may suspend or terminate your access if you violate these Terms or if necessary to protect the service. Provisions that by their nature should survive termination (including ownership, disclaimers, and limitations of liability) will survive.

12. Governing law

These Terms are governed by the laws of the State of Delaware, United States, without regard to its conflict-of-laws rules. Any dispute will be subject to the exclusive jurisdiction of the state and federal courts located in Delaware, except where applicable law requires otherwise.

13. Changes to these Terms

We may update these Terms from time to time. When we do, we’ll revise the “Last updated” date above. Your continued use of the app after changes take effect constitutes acceptance of the revised Terms.

14. Contact

Questions about these Terms? Email contact@4dhd.org.