HARMONYOS APP · OFFICIAL TEXT

Electrical Engineering Study Hub Privacy Policy

Last updated: 14 August 2026 Effective date: 14 August 2026 Applies to versions 3.0.0 and 3.0.1

This policy is written against the actual source code of Electrical Engineering Study Hub (bundle ID com.eestudy.hub). The Chinese version is the controlling text for users in the Chinese mainland.

Introduction

Electrical Engineering Study Hub is a standalone HarmonyOS study app for electrical-engineering learners. After installation you can read bundled courses, view formulas and engineering diagrams, and complete chapter quizzes without registering, signing in, or connecting to the internet.

We respect your privacy. In the current versions, this app does not collect, upload, transmit, or share personal information with the developer, any server, or any third party. Reading preferences and reading progress stay on your device so the app can restore your place.

Please read this policy before using the app. By installing or continuing to use the app, you acknowledge the data practices described here.

1. Operator and scope

This policy covers official AppGallery builds of the app and later versions that keep the same offline data practices. It does not cover the HarmonyOS system itself, the device maker’s cloud backup service, or third-party websites you may visit on your own.

2. How we handle personal information

Personal information means information recorded electronically or otherwise that relates to an identified or identifiable natural person, excluding anonymised information.

Based on the current source code and permission manifest:

• The app does not create accounts or ask for your name, phone number, email address, ID number, or other identity data;
• The app does not request internet permission and contains no HTTP/HTTPS requests, remote APIs, content downloads, or upload code;
• The app does not read contacts, SMS, call logs, the photo library, camera, microphone, location, clipboard, or calendar;
• The app does not collect OAID, AAID, IMEI, MAC address, advertising IDs, or other tracking identifiers;
• The app does not include advertising, analytics, crash-reporting, remote-config, push, payment, social-login, or sharing SDKs;
• Quiz answers exist only in memory on the current screen. They are not persisted and are not uploaded.

Conclusion: this app does not collect personal information. Local reading settings cannot identify you by themselves and are never sent to the operator.

3. Actual app features

The following features exist in the source code and explain why a few preferences are stored locally:

1. Browse a bundled course library (13 courses, 113 chapters, 513 knowledge units, and 233 quiz questions);
2. Read course text in single-page or continuous modes, with horizontal or vertical paging;
3. View bundled course images and engineering diagrams, including in-app preview and zoom;
4. Render mathematics: prefer pre-baked formula images shipped in the package; if a specific image is missing, fall back to a local KaTeX page on the device;
5. Complete chapter quizzes locally and check answers on the device;
6. Switch among light, eye-care, and dark themes, and adjust text and formula size;
7. Reorder the home course list and remember the last reading position;
8. On 2-in-1 devices, use freeform windows, wide layouts, mouse hover, and keyboard navigation;
9. Optionally enable a low-end mode that reduces motion.

Course text, images, diagrams, fonts, and formula assets are all shipped in the install package. The app does not download learning content from the internet.

4. System permissions

The module manifest does not declare requestPermissions. The packaged profile does not include ohos.permission.INTERNET or other sensitive or ordinary permissions. The app does not show permission prompts.

5. Local storage

To restore your reading habits, the app uses HarmonyOS PersistentStorage on the device. This data is not uploaded and is removed when you uninstall the app or clear its data.

On upgrade, the app deletes any leftover online course-cache file from older builds and isolates the image cache under a bundled-only schema. That cleanup happens only on the device.

6. Network and the local Web component

The app does not request internet permission. The source contains no @kit.NetworkKit usage, HTTP client, remote URL, Authorization header, or token.

The embedded Web component is used only to render mathematics locally. It always loads the packaged file katex/formula.html. The referenced CSS, JavaScript, and fonts are also inside the package and do not contact any website. JavaScript, DOM storage, and file access are enabled solely so the local page can typeset formulas, report size, and perform a local fallback render. Those capabilities are not used to go online or collect personal information.

KaTeX is an open-source typesetting library copied into the app’s rawfile at build time. At runtime it does not contact KaTeX or any other third-party server.

7. Third-party SDKs and sharing

The release package has an empty business-dependency list. It does not include advertising, analytics, push, payment, social, or crash-reporting SDKs. Development-only test libraries are not shipped in the user-facing app.

We do not provide, sell, rent, or exchange personal information with any third party. Because the app does not collect personal information, there is in practice no sharing, transfer, or public disclosure. The app does not transfer personal information across borders.

8. Local use of device information

At launch the app reads the system device-type field only to detect a 2-in-1 layout. That value is not stored and is not sent off the device.

The app also reads the window avoid area and the package version name, to fit the status bar and to show the version on the settings page. Both reads stay on the device.

9. System backup and logs

The app declares a system backup extension so that, if you use HarmonyOS / Huawei ID device backup, the operating system may include the app sandbox according to system rules. The app’s own backup and restore callbacks are empty and do not package or upload extra data. Whether backup happens, and where it is stored, is controlled in system settings. It is not an app-initiated collection or transmission of personal information.

The app may write diagnostic messages through system hilog, for example when a window setting fails. Those messages remain in the device log framework. The app has no code that uploads logs.

10. Security and retention

Because data remains in your app sandbox, retention follows how you use the device:

• Reading settings and progress remain until you uninstall the app, clear app data, or reset them yourself;
• Image and formula caches are created during use and are removed on uninstall, data clearing, or a local schema upgrade;
• Quiz state is discarded when you leave the current quiz screen.

We do not store any of your data on our own servers, and there is no operator-side cloud account or remote database.

11. Your rights

Where applicable law grants rights to be informed, to decide, to access, to copy, to correct, to delete, or to withdraw consent, you may exercise them. Because this app does not collect personal information, there is ordinarily no personal data held by the operator. You can still manage on-device data as follows:

• Change or restore theme, type size, reading mode, and course order in Settings;
• Clear the app’s data in system settings, or uninstall the app, to delete all local preferences and caches;
• Turn off system backup if you do not want the OS to include this app’s sandbox in a device backup.

If you believe this policy does not match the app’s behaviour, or you wish to exercise other legal rights, contact us using the details below. We will review and respond as required by law.

12. Children

The app provides electrical-engineering study materials. It has no social features, live streaming, user-generated content, location services, or online commerce. We do not seek to collect personal information from children. Guardians may supervise use and can limit screen time with system tools.

If a guardian wants local data removed, clear the app data or uninstall the app, or contact us for instructions.

13. Updates to this policy

If a future version adds networking, accounts, permissions, or any personal-information processing, we will update this policy before that feature is enabled and will give notice or obtain consent as required by law. The updated policy will be published at this URL with a new update date.

Editorial clarifications that do not change data practices may be published here without a separate notice.

14. Contact

This app is operated by the individual developer Jingyi Dai (戴靖宜).

For questions, complaints, or rights requests, use the developer contact details shown on the Electrical Engineering Study Hub listing in Huawei AppGallery.

Please include the app name, bundle ID, and a short description of your request so we can identify the version.

Schedules

Schedule A. Personal information collection list

Schedule B. Third-party sharing list

None. The app does not share personal information with third parties.