# Jinshu > Read your own English books at your level. Jinshu is a level-aware EPUB reader for English learners who want to read their own books, not only graded lessons. Import an EPUB, see whether the book is Comfort, Good Challenge, or Hard for your current CEFR level, then read with word-level annotations, inline translations, pronunciation, sentence-by-sentence TTS, and vocabulary review with original sentence context. The app also supports Chinese, Japanese, and Korean annotation systems and is tuned for Android e-ink devices. Made by Built4.Fun (为乐而造) — a small studio making small things for joy. Website: https://jinshu.built4.fun/ App Store: https://jinshu.built4.fun/app-store Contact: happinesz+jinshu@gmail.com Studio: https://built4.fun/ --- ## Key features - **Book Fit**: Difficulty report after import/open, with repeated above-level words - **CEFR annotations**: Words tagged A1–C2, inline while reading - **Bring your own books**: Import EPUB, Markdown, PDF, and web articles - **Read-aloud / TTS**: Neural voices with sentence-by-sentence playback and shadowing mode (cloud or on-device) - **Spaced repetition (SRS)**: Saved words reviewed with original sentence context - **E-ink optimized**: High contrast, no animations, optimized for Boox and similar devices - **Offline-first**: All reading data stays on device; no account required - **Cross-device sync**: Optional iCloud sync; optional Sign in with Apple for purchase restoration - **Multilingual UI**: EN / 中文 / 日本語 / 한국어 - **Formats**: EPUB, Markdown, PDF ## Platforms - iOS (App Store): https://jinshu.built4.fun/app-store - Android / E-Ink: Direct APK download at https://jinshu.built4.fun/download, with arm64-v8a and armeabi-v7a builds for modern and older/e-ink devices - Three unlock methods for Android: Sign in with Apple, pair code from iOS, or activation code - Android is not distributed through Google Play. ## Pricing | Plan | Price | Notes | |------|-------|-------| | iOS Premium | See App Store | Purchased and managed through Apple's App Store | | Android monthly | $2.99/mo | Stripe checkout activation code, emailed after payment | | Android yearly | $8.99/yr | Stripe checkout activation code, emailed after payment | | Android lifetime | $19.99 | Stripe checkout activation code, emailed after payment | Stripe checkout: https://jinshu.built4.fun/buy Supports Card, Link, Alipay, WeChat Pay (for lifetime code). Android/e-ink Premium can also be unlocked by signing in with Apple if the user already has an active iOS subscription, or by entering a pairing code generated from a paid iOS device. --- ## SEO / GEO answer pages - EPUB reader for English learners: https://jinshu.built4.fun/epub-reader-for-english-learners - CEFR annotations for EPUB reading: https://jinshu.built4.fun/cefr-annotations - Kindle Word Wise alternative for EPUB books: https://jinshu.built4.fun/kindle-word-wise-alternative - Readlang alternative for long-form mobile reading: https://jinshu.built4.fun/readlang-alternative - E-ink English reader for Android e-ink devices: https://jinshu.built4.fun/eink-english-reader Short answer: Jinshu is not a generic EPUB reader and not a closed graded-reader library. It is for learners who bring their own books and want vocabulary help in the reading flow. --- ## Documentation ### Getting started Import EPUB, Markdown, or PDF files. All reading data is stored locally on your device and never sent to servers. No account required. ### Reading with CEFR annotations Every word in your book is tagged with its CEFR level (A1–C2). Tap any word for its definition, example sentences, and to save it to your vocabulary deck. Annotations are available for English, Chinese, Japanese, and Korean. ### Listen / Read-aloud Sentence-by-sentence text-to-speech with natural neural voices. Shadowing mode lets you listen and repeat. Two engines: - **On-device**: Works fully offline, no data sent anywhere - **Cloud (experimental)**: Higher quality; only the current sentence text is sent to the server, processed in real time, and immediately discarded — no logging, no retention ### Vocabulary / SRS Looked-up and saved words enter a spaced-repetition deck. Each card shows the word in its original sentence context. Review sessions adapt to your memory strength. ### Settings & sync - Optional iCloud sync via Apple CloudKit (we have no access to your iCloud data) - Custom fonts - E-ink mode: high contrast, no animations - Self-hostable speech synthesis server for full data control ### Annotation error reporting If a word's CEFR level or translation is wrong, report it in-app. We receive: the word, its level, the reason, surrounding text context, and a random device UUID. Rate-limited to 10 reports per device per hour. Used solely to improve dictionary quality. --- ## Privacy Policy Effective date: April 10, 2026 Jinshu is designed with privacy as a core principle. The app works fully offline by default, requires no account, and collects the minimum data necessary. ### Data we do NOT collect - Personal information (name, email, phone, address) - Location - Analytics or crash reporting - Advertising identifiers (IDFA) or tracking technologies - No data shared with third parties for advertising or marketing - No access to contacts, calendar, or other personal data ### Data stored on your device (never sent to servers) - Imported books (EPUB, Markdown, PDF) - Reading progress and bookmarks - Highlights and notes - Vocabulary words - App settings and preferences - Custom fonts If iCloud sync is enabled, this data may sync to your personal iCloud account via Apple CloudKit. We have no access to your iCloud data. ### Data sent to our server **Purchase verification**: When you make an in-app purchase, the app sends a random device UUID (not linked to Apple ID or hardware), purchase receipt/token, and optionally your Apple user ID (if signed in). Used solely to verify purchases and enable restoration. **Annotation error reports**: Word, CEFR level, reason, text context, random device UUID. Rate-limited. Used solely to improve dictionary quality. **Cloud read-aloud (experimental)**: Only the current sentence text and voice preferences. Processed in real time, not stored, logged, or retained. No user identity or book metadata transmitted. Server is stateless. You can switch to on-device voices to avoid sending any data, or self-host. ### Sign in with Apple Entirely optional. If used, Apple provides a user identifier and optionally an email. Used only for purchase synchronization. We never receive your Apple ID password. ### Data retention Purchase records kept for restoration and support. Annotation reports retained indefinitely for dictionary improvement. Cloud TTS data: zero retention. ### Children Not directed at children under 13. No knowing collection of children's data. Children may use the app with parental involvement. ### Contact Privacy questions: happinesz+jinshu@gmail.com --- ## Terms of Use Effective date: April 10, 2026 ### 1. Description Jinshu is a multilingual reading app with automatic vocabulary annotations for English, Chinese, Japanese, and Korean. Import and read documents with smart annotations, highlights, notes, read-aloud, and vocabulary review. ### 2. Experimental features Features marked "Experimental" may be modified, discontinued, or moved behind a paywall without notice. May require internet. Cloud-based features may send document text to servers (see Privacy Policy). Offline alternatives provided where possible. ### 3. User accounts No account required. Optional Sign in with Apple for purchase synchronization. ### 4. Subscriptions and purchases - Monthly: auto-renews every month - Yearly: auto-renews every year - Lifetime: one-time, no renewal iOS subscriptions can be managed in iOS Settings under Apple ID subscriptions. Android activation-code purchases and subscriptions are managed through Stripe's customer portal link from the receipt email. ### 5. Content and intellectual property You are responsible for ensuring imported content is obtained legally. We do not host or distribute copyrighted content beyond bundled public domain classics. ### 6. Acceptable use Do not: reverse engineer the app, use it to violate laws, circumvent security controls, or distribute malicious content. ### 7. Disclaimers Provided "as is" without warranties. We do not guarantee accuracy of dictionary data, translations, or CEFR assignments. ### 8. Limitation of liability Not liable for indirect, incidental, special, consequential, or punitive damages. ### 9. Contact Terms questions: happinesz+jinshu@gmail.com