Moon+ Reader alternative
GemReader vs Moon+ Reader · Android · Updated September 2026
The short answer
GemReader is a free Android EPUB and PDF reader with no ads and no Pro tier. Choose it over Moon+ Reader if you read to learn: it turns highlights into a spaced-repetition flashcard deck, saves your answers inside interactive workbooks, imports Anki decks, and keeps every book AES-256 encrypted on the phone.
Stay on Moon+ Reader if you need cloud sync across devices, FB2, TXT or CBR support, or the deepest display customisation on Android. Moon+ has been refined for over a decade and those are areas where it is simply ahead.
Why people look for a Moon+ Reader alternative
Three complaints come up again and again. The free version shows ads, and the Pro upgrade is what removes them. The settings screens are so deep that a new reader spends its first evening configuring rather than reading. And highlights and notes are stuck inside the app: you can export them as a text file, but you cannot do anything with them there.
GemReader answers each directly. There is nothing to pay for and no ad slot to fill. Typography, margins and themes are set automatically per book, with a handful of overrides rather than a hundred. And highlights are the point of the app, not a side feature: every one you make is a card on a Review page, ready to drill without exporting anything.
Feature by feature
A dash means partial — the feature exists with a caveat given in the note.
| Feature | GemReader | Moon+ |
|---|---|---|
| PriceGemReader: free, no paid tier. Moon+: free with ads, Pro is a one-time purchase | ||
| No adsMoon+ shows ads in the free version; Pro removes them | ||
| EPUB and PDF in one libraryMoon+ opens PDFs in a separate viewer with fewer of its reading features | ||
| Comics (CBZ)Both read .cbz. Moon+ also opens .cbr; GemReader ships two public-domain comic catalogs in-app | ||
| FB2, TXT, DjVu, HTMLMoon+ wins on breadth of text formats | ||
| Full EPUB 3 renderingCSS layouts, custom fonts, scripts, fixed layout, media overlays | ||
| Workbook answers savedForm fields in interactive EPUBs persist between sessions | ||
| Highlights → flashcardsBuilt-in spaced repetition, plus Anki .apkg/.txt import | ||
| Text-to-speechBoth. GemReader also attaches custom audio per chapter | ||
| Built-in dictionaryBoth look words up without leaving the page | ||
| Free book catalogs (OPDS)Both browse Gutenberg-style catalogs in-app | ||
| Cloud syncMoon+ syncs via Dropbox, Google Drive or WebDAV. GemReader has no cloud — device-to-device transfer only | ||
| Reading customisation depthMoon+ has far more knobs: themes, gestures, margins, animations | ||
| Books encrypted on deviceAES-256 on import; never stored as plaintext | ||
| PIN-locked private foldersHidden shelves that wipe after 3 wrong PINs | ||
| No telemetry or ad SDKsGemReader ships no analytics or crash reporting | ||
| Android versionGemReader needs Android 10+. Moon+ supports older devices | ||
| iOS / desktopNeither today. GemReader for iPhone and iPad is in testing; Moon+ is Android-only |
Where Moon+ Reader is still better
- Sync. Moon+ keeps reading position, highlights and notes in step across devices through Dropbox, Google Drive or WebDAV. GemReader has no cloud at all; Gem Beam moves a library between two devices over local Wi-Fi, once.
- Formats. FB2, DjVu, CBR, plain TXT and HTML all open in Moon+. GemReader opens EPUB, PDF, MOBI, AZW, AZW3 and CBZ and nothing else.
- Customisation. Page-turn animations, gesture mapping, per-corner tap actions, dozens of themes. GemReader deliberately keeps this short.
- Older phones. Moon+ runs on Android versions GemReader no longer supports; GemReader needs Android 10 or newer.
What GemReader does that Moon+ Reader doesn’t
- Highlights become flashcards. Every highlight and note is a card on a built-in spaced-repetition Review page. Existing Anki decks (.apkg, .txt) import and drill alongside them.
- Workbooks that remember. Text fields, checkboxes and selects inside an EPUB 3 workbook are saved automatically and survive closing the app.
- Full EPUB 3.3. CSS layouts, embedded fonts, scripts, fixed-layout pages and media overlays render as the publisher built them, which matters for textbooks and language courses.
- Encrypted library. Every book is AES-256 encrypted on import and decrypted only in memory. PIN-locked folders hide sensitive reading and wipe their keys after three wrong guesses.
- Nothing phones home. No analytics, no crash reporting, no ad SDK. The privacy policy is short because there is nothing to disclose.
Switching from Moon+ Reader
Install GemReader, open it, and import the EPUB and PDF files from wherever Moon+ kept them — usually a Books folder in internal storage. Each file is encrypted as it comes in. Not sure whether a file will open? Drop it into the free Book Checker first; it flags DRM and corrupt containers in your browser without uploading anything.
Highlights made in Moon+ stay in Moon+. There is no importer for its export format, so keep the app installed until you have re-marked what matters, or export the notes as text for reference.
Questions people ask
If you read to study — textbooks, language material, lecture PDFs — yes: it turns your highlights into a spaced-repetition deck, saves workbook answers inside interactive EPUBs, and has no ads or Pro tier. If you mostly want cloud sync between devices, FB2/TXT/DjVu support, or hundreds of display settings, Moon+ Reader Pro remains the stronger choice.
Free forever. There is no Pro tier, no ads, no in-app purchases and no subscription. Moon+ Reader's free version shows ads; the Pro version is a one-time purchase that removes them and unlocks a few features.
Your book files, yes — import the EPUB, PDF, MOBI or AZW3 files from your phone's storage or a folder. Moon+ highlights and notes do not transfer automatically; Moon+ can export them as text, but there is no importer for that format in GemReader.
Not through the cloud. GemReader has no account and no server. To move to a second phone or tablet, use Gem Beam: the two devices connect directly over Wi-Fi and the whole library — books, highlights, notes, reading position and study progress — is sent across encrypted. It is a one-time transfer, not continuous sync.
EPUB (full EPUB 3.3), PDF, MOBI, AZW, AZW3 and CBZ comic archives. It does not open FB2, CBR, DjVu or plain TXT — Moon+ Reader does.
GemReader. It was built for that use: interactive workbook answers are saved automatically, six highlight colours with typed notes become a flashcard deck on a Review page, existing Anki decks import, and lecture PDFs live in the same library as the EPUBs.
The reader built for studying
Textbooks, lecture PDFs and workbooks in one library. Highlight as you read, then study those highlights as flashcards — without exporting anything or leaving the app. Free, no ads, no account.