Haku

A clear agreement

Terms of Use

These terms set the ground rules for using Haku. They are intentionally concise and should be read together with Apple’s standard license terms.

Effective August 24, 2026

1. Agreement

Haku is provided by the developer identified as the seller on Haku’s App Store product page (“Haku”, “we”, “us”). By downloading or using Haku, you agree to these Terms and the Apple Standard End User License Agreement (“Apple Standard EULA”).

These Terms supplement the Apple Standard EULA. The Apple Standard EULA controls the license to the app and applies where these Terms do not address a subject. Mandatory consumer rights that apply where you live are not limited by these Terms.

If you are not legally able to accept these Terms on your own, use Haku only with permission and supervision from a parent or legal guardian.

2. What Haku provides

Haku lets you write, encrypt, schedule, store, synchronize, export, and later read letters and related content. Some features require a compatible Apple device, an Apple account, iCloud, iCloud Keychain, notifications, or permissions you control in system settings.

Haku grants no rights beyond those provided in the Apple Standard EULA. The app, website, visual identity, and original software remain the property of Haku’s developer and applicable licensors.

3. Your responsibilities

You agree to:

  • use Haku lawfully and only on devices and accounts you are authorized to use;
  • protect your devices, Apple account, recovery key, and exported files;
  • avoid attempting to disrupt, overload, bypass, probe, or misuse Haku or its supporting services;
  • avoid using Haku to store or distribute content that infringes rights, violates law, or is intended to harm another person; and
  • maintain independent copies of content that would cause serious harm if lost.

4. Your content

You retain ownership of the letters, attachments, responses, and other content you create. You give Haku only the limited permission necessary to process that content on your device and through the service providers described in the Privacy Policy so the requested features can work.

You are responsible for your content and for having the rights required to store it. Haku’s developer does not routinely access or moderate encrypted letter content and may be technically unable to recover it for you.

5. Third-party services

Haku uses Apple services such as CloudKit, Keychain, notifications, maps, photos, and the iTunes Search API. This website is delivered through Cloudflare. Those services are governed by their own availability, terms, and privacy practices.

Links or search results from external services are provided for convenience. Haku does not control their content, accuracy, availability, or future behavior.

6. Availability, delivery, and backups

A scheduled letter is not a guaranteed messaging or archival service. Delivery can be delayed or prevented by device state, notification settings, software changes, iCloud availability, account changes, network conditions, corrupted data, or events outside Haku’s control.

Haku may change, suspend, or discontinue features when reasonably necessary. Where practical, material changes will be communicated through the app or website. You should keep your recovery key and export backups of important content.

7. Warranty and liability

To the maximum extent permitted by applicable law, Haku is provided “as is” and “as available.” We do not promise uninterrupted operation, permanent storage, exact notification timing, or recovery of deleted or inaccessible content.

Warranty exclusions and liability limitations in the Apple Standard EULA apply to your use of Haku. Nothing in these Terms excludes or limits liability that cannot legally be excluded, or any mandatory warranty or consumer right that applies to you.

8. Ending use and changes

You may stop using Haku at any time. You can delete individual content, erase the vault through the app, and uninstall Haku. Uninstalling alone may not delete synchronized iCloud data or files you previously exported.

Your right to use Haku may end if you materially violate these Terms or the Apple Standard EULA. Provisions that by their nature should continue—such as ownership, disclaimers, and responsibility for prior conduct—survive termination.

We may update these Terms as the app, providers, or law changes. The effective date will be revised. Continued use after updated Terms take effect means you accept them, except where applicable law requires another form of consent.

9. Contact

For questions about Haku or these Terms, use the current support contact shown on Haku’s App Store product page.