Last updated: October 11, 2026
This Privacy Policy explains how NgheRo.Vn (“we”, “us”, or “our”) handles information when you use English Book Reader AI & Learn (the “App”). The App helps you read English books and documents, listen with text-to-speech, translate sentences, and learn vocabulary, phrases, and grammar from the content you choose.
By using the App, you agree to the practices described in this Privacy Policy.
Information We Collect
Books, documents, and reading content
The App lets you import or create reading content, including PDFs, pasted text, scans, photos, and notes. Your library content, reading progress, marks, highlights, playback state, saved learning cards, voice settings, language settings, and app preferences are stored on your device where possible.
Text is extracted from supported files so the App can display it, read it aloud, and help you learn from it. For scanned pages or photos, the App may use text recognition (OCR). Reading and offline text-to-speech are designed to run on your device. We do not use your book or document content for advertising, and we do not sell it.
When you use AI vocabulary, phrase, grammar, dictionary, or sentence translation features, the App may send selected sentences, surrounding context, document identifiers, your learning language, your native language, and your selected learning level to our backend at api.nghero.vn so the learning analysis can be generated. These requests are used to provide the feature, enforce access limits, improve reliability, and prevent abuse. They are not used for targeted advertising.
If you delete documents or saved cards in the App or uninstall the App, locally stored data may be removed according to your device operating system’s behavior.
Voice model downloads and cached audio
Some voices are included with the App. Other voices or model files may be downloaded once and then used offline on your device. Downloads may be fetched from file-hosting services we use to distribute model files, such as GitHub Releases or similar providers. Like any file download, the hosting provider may receive technical information such as your IP address and the requested file.
The App may cache generated audio for sentences you have already heard so playback can resume quickly. Cached audio is stored on your device and can be cleared in the App where the feature is available.
Purchase, subscription, and trial information
If you start a free trial, subscribe to a paid plan, restore a purchase, or otherwise use paid access, your payment and subscription management are handled by Apple App Store or Google Play. We do not receive or store your full payment card details. Paid access in the App is sold as auto-renewable subscriptions; the current plans, prices, and billing periods are shown in the App and described in our Terms of Use.
To activate, validate, or restore access, the App sends purchase and entitlement information to our backend at api.nghero.vn, such as:
- product identifier;
- purchase token, transaction identifier, or receipt data;
- purchase or subscription status;
- platform;
- app identifier and app version;
- the random device identifier described below.
The App currently offers free AI vocabulary analysis for 7 days, covering up to the first 1,000 words of each book. A paid subscription continues AI vocabulary, phrase, grammar, and translation analysis beyond those limits. We use access and usage records to provide the trial, validate subscriptions, restore entitlements, prevent fraud, debug purchase issues, and provide the features you requested.
Device identifier
The first time you open the App, it generates a random identifier and stores it on your device. It is not your advertising identifier (IDFA), and it is not derived from your name, email, or hardware serial number. We use it to link purchase validation, trial activation, learning analysis access, usage analytics, push notification registration, support conversations, and crash reports to the same app installation. It may reset if you uninstall the App or clear its data.
Usage analytics
The App sends basic usage events to our backend, such as screens opened, buttons or options tapped, import and reading events, learning feature status, app lifecycle events, app version, platform, and the device identifier. We use these events to understand which features are used, improve the App, debug issues, and prevent abuse.
The App also includes Firebase Analytics. The device identifier may be set as a Firebase user ID or user property so events and crashes can be associated with the same installation. Firebase may process an app instance identifier and technical device information. The App does not request the advertising identifier and does not track you across other companies’ apps or websites for advertising.
Diagnostics and crash data
The App uses Firebase Crashlytics and similar diagnostics to help us find and fix crashes and serious errors. Crash reports may include technical information such as device model, operating system version, app version, crash logs, stack traces, error context, and the device identifier.
Crash and diagnostic data are used to improve reliability and troubleshoot issues. We do not use crash data for advertising.
Support messages and attachments
If you contact support from inside the App, we receive the message you write, any photos or attachments you choose to include, the device identifier, platform, app version, and any replies we send back. The App asks for photo library or camera access only when needed for import, scan, or support attachment features. Please do not include sensitive information in support messages or attachments that you do not want us to see.
We use support information to answer your request, diagnose issues, and improve the App. Support conversations may be retained so we can follow up.
Notifications
The App may ask for notification permission, for example to send support replies or app updates. If you allow notifications, the App registers a push notification token through Firebase Cloud Messaging and, on iOS, Apple Push Notification service. The token may be sent to our backend with the device identifier, platform, and app version. If you tap a notification, the App may tell our backend that it was opened. You can change notification permission at any time in your device settings, and the App works without notification permission.
Automatically collected technical information
Some technical information may be collected automatically by the App, operating system, app store, Firebase services, or our backend when required for app operation, security, diagnostics, purchase validation, access control, or compliance, such as IP address, device model, operating system version, language, locale, app version, and request timestamps.
How We Use Information
We use information to:
- provide, maintain, and improve the App;
- import, store, display, and play your reading content;
- remember reading progress, saved learning cards, and settings;
- generate vocabulary, phrase, grammar, dictionary, and translation results you request;
- validate trials, purchases, subscriptions, and restored access;
- enforce fair-use limits and prevent abuse;
- understand feature usage through analytics;
- respond to support requests and send notifications you allow;
- diagnose crashes, bugs, and performance problems;
- comply with legal, tax, accounting, and platform requirements.
Sharing of Information
We may share limited information with service providers that help operate the App, including:
- Apple and Google for app distribution, in-app purchases, subscriptions, refunds, and account-level purchase management;
- Firebase/Google for analytics, crash reporting, and push notification delivery;
- Apple Push Notification service for notifications on iOS;
- GitHub or similar hosting providers for voice or model downloads;
- NgheRo.Vn backend services for purchase validation, trial activation, entitlement management, AI learning analysis, usage analytics, support, and notifications;
- infrastructure providers that host our API, databases, logs, or file storage.
We may also disclose information if required by law, legal process, platform rules, or to protect our rights, users, and services.
We do not sell your personal information. We do not use your book or document content for targeted advertising.
Third-Party Services
The App may use third-party services governed by their own policies, including:
- Apple App Store;
- Google Play;
- Firebase Analytics, Firebase Crashlytics, and Firebase Cloud Messaging;
- Apple Push Notification service;
- GitHub or similar file-hosting services;
- React Native and related platform libraries;
- AI, cloud, or infrastructure providers used by our backend to provide learning analysis.
Your use of app stores, operating-system services, and third-party services is also subject to their own privacy policies and terms.
Data Retention
Locally stored documents, reading data, saved cards, settings, and cached audio remain on your device until you delete them in the App, clear app data, or uninstall the App, subject to your operating system’s behavior.
Backend records related to purchases, subscriptions, trial activation, access checks, AI learning analysis, analytics, support, notification delivery, and diagnostics may be retained for as long as needed to provide access, support refunds and disputes, comply with legal obligations, prevent fraud, improve reliability, and operate the App.
Security
We use reasonable technical and organizational measures to protect information. However, no method of storage or transmission is completely secure. You are responsible for keeping your device, app store account, and backups secure.
Your Choices
You can:
- delete imported books, documents, notes, and saved learning cards from the App;
- clear cached audio where the App provides that control;
- manage notification permissions in your device settings;
- choose whether to use online AI vocabulary, grammar, and translation features;
- manage or cancel subscriptions through Apple App Store or Google Play;
- decline to attach photos or contact support;
- request access to or deletion of information we control by contacting us;
- uninstall the App to remove local app data, subject to backups and operating-system behavior.
Children’s Privacy
The App is not directed to children under 13. We do not knowingly collect personal information from children under 13. If you believe a child has provided personal information to us, please contact us so we can take appropriate action.
International Users
Your information may be processed in countries other than the country where you live. These countries may have different data protection laws. Where required, we take steps intended to protect your information according to applicable law.
Changes to This Policy
We may update this Privacy Policy from time to time. If we make material changes, we will update the “Last updated” date and may provide additional notice where required.
Contact Us
If you have questions about this Privacy Policy, please contact us:
- Email: [email protected]
- Developer / Publisher: NgheRo.Vn, operated by Cao Vu Hung as an individual household business (Household Business Registration No. 41L8042932, Ho Chi Minh City, Vietnam)
- Website: https://nghero.vn
See also our Terms of Use for the rules governing your use of the App.