Comparison

CalibReader vs Sumi Book

Price, ratings, monetisation and update history for both apps, side by side — with what reviewers say about each.

Head to head
About

CalibReader

This app offers a reading experience for EPUB and PDF files, featuring dual-page spreads and realistic page curls. It integrates with your existing calibre library and supports various cloud storage options. Enjoy a customizable reading environment and seamless syncing across devices.

Highlights
  • Dual-page spread and page curl effect
  • Calibre library integration
  • Cloud storage support (iCloud, Dropbox, OneDrive)
  • Cross-device reading position sync
  • Customizable themes and fonts
  • Built-in dictionary
  • PDF reader with two-page spreads
Features
Currently charting
Read full description

Read your EPUBs like a real book: two pages side by side on iPad and iPhone Duo, with real page curls. PDFs open as two-page spreads too. Open your ebook files straight from Files, Safari, Mail or AirDrop, or bring your whole calibre library: CalibReader shelves them with covers and series, and keeps your place on every device. BUILT FOR IPHONE DUO Open iPhone Duo and your book becomes a two-page spread, with real page curls. Close it and the book closes: the cover screen shows its cover, leather-bound with the title in gold or the original art. Tap to keep reading, one page at a time. Your place holds through every fold, and turning the open phone to portrait gives you a single page. YOUR EPUB AND PDF FILES Any folder of EPUB or PDF files becomes a library with covers, sorting and search. WORKS WITH YOUR CALIBRE LIBRARY Point CalibReader at your calibre library folder and every book, cover, series, tag and synopsis appears as you organised it. Nothing to convert, no lock-in. YOUR STORAGE, YOUR CHOICE • A folder on your device or in iCloud Drive • Dropbox and OneDrive • Your own server or NAS over SMB • Other apps that share a folder in Files A READER BUILT FOR LONG SESSIONS • Two-page spread, single page or continuous scroll, with page curl or flip • Opens on a title page that turns over like a real one • Parchment, sepia, black and navy themes, or your own colour • Font, size, spacing, margins and justification, applied live • Table of contents, chapter navigation, clock and progress footer • Built-in dictionary • A PDF reader with two-page spreads on iPad and iPhone Duo that remembers your page PICK UP WHERE YOU LEFT OFF Reading positions and read status sync across your devices through a tiny file in your library folder. Put down the iPad, pick up the iPhone. A free calibre plugin writes read status, % read and last-read date back to your desktop library. A LIBRARY THAT LOOKS LIKE A LIBRARY Home with continue reading and recently added; grid, list and series views; filters and search; cover art found automatically when a book has none, and Choose Cover to swap in another edition's cover or bind any book in leather. 3 BOOKS FREE, THEN ONE PURCHASE Read any 3 books free, and bring in, sync and browse as many as you like. Then unlock your whole library with one purchase. No subscription, no account, no ads, no tracking, and no data collected. Formats: EPUB and PDF in the built-in reader; other formats open in the app of your choice. Note: CalibReader opens EPUB and PDF files without copy protection (DRM). Books bought in other apps' stores stay in those apps. CalibReader is an independent app, not affiliated with or endorsed by the calibre project. calibre is a trademark of Kovid Goyal. Support: hello@calibreader.com · https://calibreader.com

About

Sumi Book

Features
Read full description

Sumi is a beautifully crafted, native reader for the manga and comics you already own or have the right to read. Sumi comes empty by design: no catalog, no content, no built-in sources — you decide what to read. Import your own files, connect your own server, or add a source by pasting the address of a site you are entitled to access. Sumi brings the reading; the library is yours. A READER, NOT A LIBRARY • Your own .cbz, .cbr, .zip, .pdf and .epub files, from the Files app, AirDrop or Mail • Your own Komga or Suwayomi server • Your own source: paste a site's address, or share a page from Safari — no content or site is included: Sumi recognizes common site software as soon as you paste an address • "Test this source" shows which step fails, and Sumi notices when a site moves DESIGNED FOR READING • Ink, dark, and Paper, light: two themes made for long sessions • Paged or vertical-scroll reading, right to left for manga, and Guided View, panel by panel • Resume: the titles you're reading at the top of your Library, back to the exact page • An end-of-chapter page, bookmarks, and tap zones your way • Rate titles from one to five seals and keep a private note • On iPad, Sumi follows the size of its window, and the keyboard turns the pages • Free backup and restore of your whole collection THE NOTEBOOK Four tabs: Library, Browse, Notebook and Settings. The Notebook keeps track of your reading, like the seal books travellers have stamped from temple to temple: • Twenty-eight ink seals to earn by reading, a few of them secret • A forgiving daily streak, a weekly goal, and challenges for the month • The ink calendar, your ex libris and the year's Almanac, to share as pictures • "What to read tonight?": the omikuji draws a title from your pile • No account, no leaderboard: it all stays yours, and "Plain reading" hides the play when you just want to read BEYOND THE APP • The Resume reading widget takes you back to the right page • Siri, Shortcuts, Spotlight search and quick actions on the app icon THE FINE PRESS (PREMIUM) • Offline downloads, from your Komga or Suwayomi server too, with predictive download and storage management • iCloud sync across iPhone and iPad • New chapters in the background, the visual selector and Change source • Continuous reading, on to the next chapter by itself, two-page spreads, color filters, page previews • Detailed statistics, unlimited history, the whole year in the ink calendar, the Almanac month by month, the seals of the seasons • Streak and seal widgets, and the Papier, Hanko and Sakura app icons • Incognito mode, App Lock with Face ID, Touch ID or a passcode, the Sakura theme and an automatic theme Seals, the streak, the weekly goal, the omikuji and the Resume reading widget stay free. SUBSCRIPTIONS The Fine Press is available as a monthly or annual auto-renewing subscription, or as a one-time lifetime purchase. Payment is charged to your Apple Account. Subscriptions renew automatically unless canceled at least 24 hours before the end of the current period; manage or cancel them in your Apple Account settings. YOUR RESPONSIBILITY Sumi is a neutral reading tool. It is not affiliated with any website, publisher, or content, and cannot guarantee the availability of any third-party source. You are responsible for ensuring you have the right to access whatever you add. Please support the authors and publishers you love. Terms of Use (EULA): https://www.apple.com/legal/internet-services/itunes/dev/stdeula/ Privacy Policy: https://sumi-reader.com/sumi-web/privacy

Screenshots

CalibReader4 screens
Sumi Book4 screens

Verdict

The call

The clearest difference is chart position: CalibReader at #136 against Sumi Book's unranked. Sumi Book's advantage is iOS requirement (15.1 vs 26.2). On price, update cadence, ads and in-app purchases there is nothing between them.

Scored on Price · Rating · Positive reviews · Number of ratings · Update frequency · Ads · In-app purchases · Monetization · Best chart rank · Devices · Requires iOS

CostPrice · In-app purchases · Ads · Monetization

Both are free to download. CalibReader sells 1 one-off in-app purchase and Sumi Book sells 3 in-app purchases, starting at $3.99 per month. Whichever you choose, the download price is not the number that matters.

UpkeepUpdate frequency

CalibReader ships an update every 3 days, Sumi Book every 5 days. The most recent releases landed on November 8, 2026 and November 5, 2026 respectively.

Scorecard2 real differences · 9 level
CalibReader versus Sumi Book: the parameters behind the verdict, then further details
ParameterCalibReaderSumi Book
PriceFreeFree
Rating4.3 (6 ratings) — better—
Positive reviews100.0% of reviews—
Number of ratings6 — better—
Update frequencyEvery 3 days — betterEvery 5 days
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchases—
Best chart rank#136 — better—
DevicesiPhone, iPadiPhone, iPad, iPod — better
Requires iOS26.215.1 — better
Further details — not scored
Size49 MB53 MB
Age rating4+17+
DeveloperGram 1Oktay Demir

In-app purchases

1 purchases

CalibReader

One-time1
  • Unlock All Books Forever$9.99
3 purchases

Sumi Book

Subscriptions2
  • The Fine Press — Monthly$3.991 Month
  • The Fine Press — Annual$24.991 Year
One-time1
  • The Fine Press — Lifetime$49.99

Questions

Is CalibReader free?
CalibReader is free to download, with in-app purchases available.
Is Sumi Book free?
Sumi Book is free to download, with in-app purchases available.
Do CalibReader or Sumi Book have ads?
Neither CalibReader nor Sumi Book shows ads.
Which is updated more often, CalibReader or Sumi Book?
CalibReader ships an update every 3 days, and Sumi Book every 5 days. Most recently, CalibReader was updated on November 8, 2026 and Sumi Book on November 5, 2026.

Other comparisons