Comparison

CalibReader vs purrpage. Double

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

purrpage. Double

This app offers a serene reading experience for books, PDFs, and articles. It features customizable typography, a distraction-free interface, and a smart reading companion for explanations and summaries. Listen to your content with natural voices and follow along as sentences are highlighted.

Highlights
  • Customizable typography
  • Distraction-free reading
  • Organized library for books, PDFs, articles
  • AI reading companion for explanations and summaries
  • Text-to-speech with highlighting
  • Note-taking and highlighting
  • Two-page spread on compatible devices
Features
Read full description

Duo Reader is a quiet place to read. Your books, PDFs and articles live in one calm library, set in beautiful type, with a reading companion for when a page needs a second look. READ IN COMFORT - Typography first: choose your typeface, size, spacing and margins, and every line reflows instantly - Clean, distraction-free pages that let the words lead - Pick up exactly where you left off, every time YOUR LIBRARY, QUIETLY ORGANIZED - Books, PDFs and RSS articles in one place - Folders for studying, classics, or whatever you're reading next - Search across your books and jump straight to the passage UNDERSTAND WHAT YOU READ - Select any passage to explain, define, highlight or add a note - Translate a passage and read it alongside the original - Ask Mochi, your reading companion, to summarize a chapter without leaving the page LISTEN WHEN YOUR EYES NEED A REST - Natural voices in several languages, with adjustable speed - Follow along as each sentence is highlighted EVERYTHING YOU SAVE, IN ONE PLACE Bookmarks, notes and highlights, gathered and easy to revisit. EVEN BETTER ON IPHONE DUO Unfold iPhone Duo and your page opens into a true two-page spread. Translations, Mochi and your notes sit beside the page instead of on top of it. Fold it again mid-chapter, or mid-sentence while listening, and you're still on the same line. PRIVATE BY DESIGN Mochi answers quick questions on device, so your reading stays on your iPhone. Mochi features require a device that supports Apple Intelligence. --------------------- Privacy Policy: https://leostudio.global/policies Terms of Use: https://leostudio.global/policies For technical assistance or other inquiries: support@leostudio.global

Screenshots

CalibReader4 screens
purrpage. Double4 screens

Verdict

The call

The clearest difference is rating: purrpage. Double at 5.0 against CalibReader's 4.3. purrpage. Double also leads on in-app purchases (none vs 1) and iOS requirement (17.6 vs 26.2). CalibReader's advantage is ads (none vs shown) and chart position (#124 vs unranked). On price, review sentiment and device support 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. purrpage. Double asks for nothing beyond the download.

ReceptionRating · Positive reviews · Number of ratings

purrpage. Double holds the better App Store score, 5.0 against 4.3. That said, the two scores are not equally well evidenced: CalibReader has 6 ratings behind it against 1, so its average is the more settled of the two. Written reviews split almost evenly too, at 100% and 100% positive.

UpkeepUpdate frequency

CalibReader ships an update every 3 days, purrpage. Double every 6 days. Both last shipped on November 8, 2026.

Scorecard8 real differences · 3 level
CalibReader versus purrpage. Double: the parameters behind the verdict, then further details
ParameterCalibReaderpurrpage. Double
PriceFreeFree
Rating4.3 (6 ratings)5.0 (1 ratings) — better
Positive reviews100.0% of reviews100.0% of reviews
Number of ratings6 — better1
Update frequencyEvery 3 days — betterEvery 6 days
AdsNo — betterYes
In-app purchasesYesNo — better
MonetizationFree with in-app purchasesAd-supported — better
Best chart rank#124 — better—
DevicesiPhone, iPadiPhone, iPad
Requires iOS26.217.6 — better
Further details — not scored
Size49 MB97 MB
Age rating4+4+
DeveloperGram 1LeoStudio Global

Customer experience

CalibReader

All ratings6 ratings
Positive83.3%
Neutral0.0%
Negative16.7%
Written reviews3 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

purrpage. Double

All ratings1 ratings
Positive100.0%
Neutral0.0%
Negative0.0%
Written reviews2 reviews
Positive100.0%
Neutral0.0%
Negative0.0%

In-app purchases

1 purchases

CalibReader

One-time1
  • Unlock All Books Forever$9.99
None

purrpage. Double

No in-app purchases

Questions

Is CalibReader free?
CalibReader is free to download, with in-app purchases available.
Is purrpage. Double free?
purrpage. Double is free to download, with no in-app purchases.
Which has better reviews, CalibReader or purrpage. Double?
purrpage. Double is rated higher. CalibReader averages 4.3 out of 5 from 6 ratings, while purrpage. Double averages 5.0 from 1 ratings.
Do CalibReader or purrpage. Double have ads?
purrpage. Double shows ads; CalibReader does not.
Which is updated more often, CalibReader or purrpage. Double?
CalibReader ships an update every 3 days, and purrpage. Double every 6 days. Most recently, CalibReader was updated on November 8, 2026 and purrpage. Double on November 8, 2026.

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