Privacy Policy

Privacy Policy

Version 1.1.0. Effective July 26, 2026. Last updated July 26, 2026.

1. Who we are

Zuyu is published by Nb41 Labs LLC ("Nb41 Labs", "we", "us"), an independent software company in Sheridan, Wyoming, United States. This policy explains how the Zuyu mobile app handles information. You can reach us at contact@nb41labs.com.

2. Scope

This policy covers the Zuyu mobile app. It does not cover other companies or services, including the app stores that distribute Zuyu or any website you reach by following a link. Zuyu is offered in the United States.

3. How Zuyu handles your information

Zuyu is a local-first app. The information you enter is stored on your device. Zuyu does not require an account, does not sign you in, and does not sync your health entries to a server operated by Nb41 Labs. There is no Zuyu cloud account for your records.

Information leaves your device only when you take an action that sends it, such as exporting a report, sharing or printing a file, or creating a backup file. You control those actions.

4. Information the app handles on your device

Depending on how you use Zuyu, the app stores entries such as:

• Medications you add, including names, forms, schedules, and dose information you enter.
• Doses you log and dose changes you record.
• Symptoms and daily check-in notes, including a note that you felt fine.
• Supply and refill details you enter, such as remaining amount, refill date, and refill threshold.
• Weight values you choose to record for appointment context.
• Reminders and schedule settings.
• Appointment-preparation and report content generated from your own entries.
• App settings, including privacy and app-lock preferences.

These entries are kept on the device as you wrote them. Zuyu does not convert, diagnose, or interpret them as clinical facts.

Some views combine your entries into a figure, such as a low-supply status, a count of days until a refill date you entered, or a count of scheduled medication days before a visit. These figures are produced on your device from what you entered. They are not sent anywhere.

5. What Nb41 Labs does and does not receive

Nb41 Labs does not receive your health entries. Specifically:

• Zuyu does not transmit your medications, doses, symptoms, notes, weight, supply figures, or any other health entry to Nb41 Labs.
• Zuyu contains no advertising software, no tracking software, and no attribution software.
• Zuyu does not sell personal information and does not share personal information for targeted advertising.
• Zuyu does not connect to Apple Health or Android Health Connect.
• Zuyu does not request access to your camera, microphone, photo library, contacts, calendar, or location.

If you email us for support, we receive what you choose to put in that message. Please do not include sensitive medical details when you write to us.

Two services receive limited information that is not a health entry, and each is described in full below: Sentry receives technical crash diagnostics, in section 6, and RevenueCat receives subscription status, in section 7. Neither receives your health entries.

6. Crash reporting and diagnostics

Zuyu uses Sentry to identify, diagnose, and repair app crashes and technical failures. Sentry is an error-monitoring service operated by Functional Software, Inc. When Zuyu crashes or hits a technical failure, it sends a limited technical diagnostic report to Sentry over an encrypted connection.

A diagnostic report is limited to technical information about the failure itself. It may include:

• the exception type;
• a sanitized stack trace;
• the app version and build number;
• the platform, such as iOS or Android, and the operating-system version;
• the device model class, such as a general iPhone or Android hardware class;
• the release environment;
• a coarse internal error code;
• a sanitized name for the app screen or feature area where the failure happened.

Sentry does not receive your health information or your identity. Specifically, a diagnostic report does not contain medication names, medication identifiers derived from what you entered, dose amounts, schedules, injection dates, symptoms, side effects, notes, weight, supply or refill values, report contents, exported information, backup contents, your files, or the contents of the app database. It does not contain your email address, your name, an account identifier, or an advertising identifier. Zuyu attaches no user record to a diagnostic report, and it filters each report on your device before sending it.

Sentry works out an approximate location from the internet connection your device uses to send a diagnostic report. That is a country, a region, and a city, worked out from the network address the report arrives from. It is not precise, it contains no coordinates and no street address, and Zuyu does not send it: Sentry derives it at its end. Zuyu does not use your device location and does not ask for location permission. The network address itself is not stored, and this approximation cannot be switched off on Sentry's hosted service.

Sentry is used only to fix technical faults. It is not used for advertising, tracking, behavioral analytics, product analytics, profiling, session replay, or user-feedback collection. Zuyu contains no advertising software, no attribution software, and no product-analytics software of any kind, so no screen views, feature usage, session data, or product events are collected or transmitted.

Sentry processes this diagnostic information as a service provider acting for Nb41 Labs, and is required to protect it consistently with its contractual and legal obligations. Sentry's own privacy practices are described in its privacy policy.

7. Subscriptions and app-store transactions

Zuyu offers a free tier called Essential and a paid tier called Plus. Plus is sold as an auto-renewing subscription at 9.99 US dollars per month or 59.99 US dollars per year. A Premium tier is not sold.

Payment is processed by the app store on your device, which is the Apple App Store or Google Play. Nb41 Labs does not receive your full payment-card number or your bank details. Apple and Google process purchase information under their own privacy policies.

Zuyu uses RevenueCat to manage subscriptions. RevenueCat is a subscription-management service operated by RevenueCat, Inc. It records whether a subscription is active so that Plus unlocks on your device and can be restored if you reinstall the app or move to a new device.

RevenueCat receives only the limited purchase and subscription information needed for that purpose. It may include:

• an anonymous app user identifier generated for the purchase;
• the store transaction identifier;
• the product identifier;
• the purchase date;
• the renewal status, the expiration date, and any trial status;
• the subscription entitlement status;
• the platform, the app version, and the locale;
• the offering or purchase surface the purchase came from.

RevenueCat does not receive your health information. It does not receive medication information, dose information, symptoms, notes, weight, supply information, reports, exports, backups, or any user-entered health history. Zuyu identifies a purchase only by an anonymous identifier generated for that purpose. Zuyu does not send RevenueCat your name, your email address, or an account identifier, and there is no Zuyu account to send.

RevenueCat is not used for advertising or behavioral tracking. It processes subscription information as a service provider acting for Nb41 Labs, and is required to protect it consistently with its contractual and legal obligations.

You manage, renew, and cancel a subscription through your app-store account.

8. Export, sharing, printing, and backup

Zuyu lets you export a raw copy of your data, share or print reports you generate, and create a backup file you can use to restore your data later.

When you export, share, or print, the resulting file goes wherever you send it, using your device and the apps you choose. Anyone you share a file with can read what it contains, so review it first.

A backup is a file you create and control. If you set a recovery password when you create it, the backup file is encrypted. If you do not set one, the backup file is not encrypted, so store it somewhere you control. If you save a backup or an export to a cloud service, a messaging app, or another device, that copy is subject to the settings and protections of wherever you put it, and it is no longer governed by this policy.

9. Device backups and cloud services

Zuyu does not use iCloud Drive, CloudKit, iCloud key-value storage, or any other cloud service to store or synchronize your entries. Zuyu uploads nothing.

Your device makes its own backups, separately from Zuyu. On iPhone and iPad, the backup your device creates, whether to iCloud or to a computer, may include Zuyu app data along with data from your other apps. That backup is created, encrypted, and controlled by Apple and by your device settings, not by Zuyu. You can review and change what your device backs up in your device settings. On Android, Zuyu's health database is excluded from Google's automatic app backup.

10. Retention and deletion

Because your entries are stored on your device, they remain until you delete them in the app or remove the app. Deleting the app removes the app data stored on the device.

Backups, exports, and shared files you saved elsewhere are not removed when you delete the app. You control those copies, and a copy held in a device backup follows your device backup settings. If you email us, we keep that message as long as needed to respond and to maintain ordinary business records.

11. HIPAA and this app

The Health Insurance Portability and Accountability Act, known as HIPAA, applies to healthcare providers, health plans, healthcare clearinghouses, and their business associates. Nb41 Labs is none of those things, and publishing Zuyu does not make it one.

Health-related information you enter into a consumer app is not automatically protected health information under HIPAA. Nb41 Labs does not claim to be HIPAA compliant, and this policy should not be read as a HIPAA notice. How your information is handled in Zuyu is governed by this Privacy Policy and by applicable consumer-protection and privacy law. Because Zuyu keeps your entries on your device and does not send them to us, the practical protection for your records comes from your device and from the choices you make about exporting and sharing.

12. Age requirement

Zuyu is intended for adults who are 18 years of age or older. Zuyu is not directed to children, and we do not knowingly collect information from anyone under 18. Because Zuyu does not require an account and keeps entries on the device, it does not build a profile of any user.

13. Security and its limits

Zuyu stores your data locally using device-level protections. App data is held in an encrypted on-device database, and the key for that database is held in your device's secure store. If encryption cannot be established, Zuyu stops rather than storing your records unprotected.

Zuyu also offers optional on-device protections: a lock that requires the Face ID, fingerprint, or passcode already set up on your device before the app opens, and an option to hide your content in the system app switcher. Your device performs that check and returns only whether it succeeded. Zuyu does not create its own PIN, does not receive or store your passcode, and does not receive or store your biometric data.

No security is perfect, and we do not promise that any system is impenetrable. Keeping your device locked, updated, and under your control is an important part of protecting your information.

14. Where processing happens

Zuyu is offered in the United States, and the limited processing described above takes place in the United States.

15. Changes to this policy

We may update this policy. When we do, we will change the version and the dates at the top of this page. Continued use of Zuyu after an update means the updated policy applies.

16. Contact

Nb41 Labs LLC
30 N Gould St Ste N
Sheridan, WY 82801
United States
contact@nb41labs.com