Comparison

KyBook 3 Ebook Reader vs Readest

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

Head to head
About

KyBook 3 Ebook Reader

This app is a versatile e-book reader and cataloger supporting numerous formats like EPUB, MOBI, and PDF. It offers a comfortable reading experience with customizable options, powerful annotation tools, and seamless cloud storage integration. Organize your library with tags, collections, and a handy cataloguer.

Highlights
  • Supports all major e-book formats
  • OPDS catalog access
  • Comfortable reading mode with themes
  • Powerful annotations and summary editor
  • Handy cataloguer with tagging
  • Cloud storage integration
Features
Read full description

KyBook is the application for reading and cataloging e-books in a modern, user-friendly style. KyBook supports all the major e-book formats, OPDS catalogs and Cloud Storage. Key features • All the major e-book formats • OPDS catalogs • Comfortable reading mode • Powerful annotations • Handy cataloguer • Cloud Storage Ebook Formats • EPub (DRM-free) • PDF (DRM-free) • MobiPocket and Kindle (mobi, azw3) • DjVu • FictionBook (fb2, fb2.zip) • Comic Book (cbr, cbz, cbt) • Audio Book (mp3, m4a, m4b) • Plain and rich text (txt, rtf) OPDS Catalogs • Provides access to enormous collection of free electronic books through OPDS-catalogs support. • Built-in list of well-known OPDS Catalogs • Allows add own catalog (e.g. Calibre content server) • Supports for .onion OPDS Catalogs reachable via Tor Network Comfortable reading mode • Themes, color schemes for reading (day, night, sepia and more). • Page turn with scroll, curl and slide. • Designed to be fast, energy efficient, optimized for very large books (books in millions of words) • Auto scrolling mode • Text-to-speech technology to voice any e-book EPUB/FB2/MOBI specific features • Customizable font, text size, page margins, paragraph indentation, background and more • Typography aware (hanging punctuation, hyphenations and more) PDF/DJVU specific features • Crops a page margins in manual and automatic mode • Smart zooming by double-tap • PDF Reflow on iPhone • Page text recognition (OCR) Powerful annotations • Marked text and bookmarks • Drawn annotations in any ebook (Apple Pencil support and just by touching). • Annotations exports in Markdown, HTML, PDF, RTF formats. Built-in the summary editor • Markdown formatting. • Exports summaries in Markdown, HTML, PDF, RTF formats. Working with fragments of text • Translation of separate words or complete sentences in different languages. • Search for a word definition in dictionaries. • Custom dictionaries in Dictd, StarDict and Lingvo DSL format • Full text searching in a book (textual, fuzzy and search using regular expressions). • Built-in search for a selected text on the Internet or Wikipedia. Handy cataloguer • Grouping by categories: by authors, subjects, sequences, publishers, tags, popular, recent, new, unread, reading and finished. • Tags and collections to categorize ebooks. • Search for books in the library and anywhere in the Internet. • Own folders tree and flexible bookshelf settings for layout and sorting. • Arranging books on a bookshelf by dragging. Working with a metadata and a table of contents • Automated extraction of a metadata from ebooks. • Convenient editing of a metadata. • Editing and creation (automatic or manual) of a table of contents. File Storage • Locally on the device. • In the Cloud Storage (iCloud Drive, Google Drive, OneDrive, Dropbox, Yandex Disk). • In the Local network on Shared Folders (SMB/CIFS) or on WebDAV server • Transparent caching of books in the Internet or Local network. • Supports of streaming audio books in Cloud Storage. • Content Server for accessing files on the device via a WiFi. Synchronization (requires subscription) • Syncs all ebooks metadata and files. KyBook offers the following subscriptions options: • 3 months: 4.49 USD • 1 year: 14.99 USD Prices may vary in other countries respecting your local currency exchange rate. Your subscription will be charged to your iTunes account. At the end of the term, unless auto-renewables subscriptions are disabled, your subscription will automatically renew in your iTunes account. You will be charged for the regular price of your subscription within 24 hours prior to the end of the current term. You can turn off automatic renewal in your iTunes account settings at any time, but you must do so at least 24 hours before the end of the current term. Refunds will not be provided for the unused portion of any term. Terms & Privacy policy http://kybook-reader.com/terms http://kybook-reader.com/privacy-policy

About

Readest

This app is a powerful ebook reader designed for deep thinkers and researchers. It offers advanced annotation tools, seamless device syncing, and robust library management with OPDS and Calibre support. Enjoy a distraction-free reading experience with customizable modes and multi-book viewing for enhanced study and analysis.

Highlights
  • OPDS Online Libraries
  • Calibre Integration
  • Sync Across Devices
  • Bookshelf Management
  • Customizable Reading Modes
  • Multi-Book View
  • Advanced Annotations & Highlights
Features
Currently charting
Read full description

Readest is an ebook reader for people who read a lot, and who want their books, notes and reading position on whatever device is nearest. Open EPUB, PDF, MOBI, AZW3, FB2, CBZ, TXT and Markdown in one library. Pull books from OPDS catalogs or from your own Calibre server. Read, annotate, listen, translate. Made for iPhone and iPad • CarPlay, so you can keep listening on the road with playback controls on the dashboard • Download read-aloud voices per book and listen with no connection at all • Add books from Files, Mail or any share sheet, and read them in place instead of copying them into a second library • Open up to four books at once on iPad and arrange them how you like Reading • Paginated or scrolling, with custom fonts, themes, spacing and margins • Vertical text for CJK books • Contrast and refresh tuned for e-ink screens • Full-text search inside a book Your library • Browse, search and download from OPDS catalogs and public libraries • Connect to Calibre or Calibre-Web, covers and metadata included • Organize with bookshelf groups you can rename Notes • Highlights, bookmarks and structured notes • Copy a highlight together with a deep link back to the passage • Export your annotations Listening and languages • Text-to-speech with downloadable offline voices • Translate a sentence, a page, or an entire book • Wikipedia and dictionary lookup without leaving the page Sync • Readest Cloud, or bring your own: iCloud, Google Drive, OneDrive, WebDAV, S3 • KOReader sync keeps your progress in step with your e-reader • iPhone, iPad, Mac, all other platforms and the web Readest is open source. Support: support@readest.com Privacy Policy: https://readest.com/privacy-policy Terms of Service: https://www.apple.com/legal/internet-services/itunes/dev/stdeula/

Screenshots

KyBook 3 Ebook Reader4 screens
Readest4 screens

Verdict

The call

KyBook 3 Ebook Reader and Readest both sit at 4.7 stars, but that hides the real split: 84% of Readest's written reviews are positive against 61% of KyBook 3 Ebook Reader's. Readest also leads on chart position (#209 vs unranked). KyBook 3 Ebook Reader's advantage is ratings volume (4.7K vs 195) and update cadence (every 5 days vs fortnightly). On price, rating, 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. KyBook 3 Ebook Reader sells 4 in-app purchases, starting at $4.49 per 3 months and Readest sells 9 in-app purchases, starting at $4.99 per month. Whichever you choose, the download price is not the number that matters.

ReceptionRating · Positive reviews · Number of ratings

On the App Store both sit at effectively the same score — 4.7 for KyBook 3 Ebook Reader against 4.5 for Readest. That said, the two scores are not equally well evidenced: KyBook 3 Ebook Reader has 4.7K ratings behind it against 195, so its average is the more settled of the two. Written reviews are what separate them: 61% of KyBook 3 Ebook Reader's written reviews are positive against 84% of Readest's.

UpkeepUpdate frequency

KyBook 3 Ebook Reader ships an update every 5 days, Readest fortnightly. The most recent releases landed on October 23, 2026 and October 22, 2026 respectively.

Scorecard5 real differences · 6 level
KyBook 3 Ebook Reader versus Readest: the parameters behind the verdict, then further details
ParameterKyBook 3 Ebook ReaderReadest
PriceFreeFree
Rating4.7 (4.7K ratings) — better4.5 (195 ratings)
Positive reviews60.9% of reviews84.2% of reviews — better
Number of ratings4.7K — better195
Update frequencyEvery 5 days — betterFortnightly
AdsNoNo
In-app purchasesYesYes
MonetizationFree with in-app purchasesFree with in-app purchases
Best chart rank—#209 — better
DevicesiPhone, iPad, iPodiPhone, iPad, Mac
Requires iOS11.0 — better16.4
Further details — not scored
Size53 MB58 MB
Age rating17+4+
DeveloperKonstantin BukreevBilingify LLC

Customer experience

KyBook 3 Ebook Reader

All ratings4,616 ratings
Positive91.6%
Neutral3.2%
Negative5.2%
Written reviews676 reviews
Positive60.9%
Neutral10.1%
Negative29.0%

Readest

All ratings191 ratings
Positive86.4%
Neutral5.2%
Negative8.4%
Written reviews285 reviews
Positive84.2%
Neutral5.3%
Negative10.5%

Bugs and requests

KyBook 3 Ebook Reader

Reported bugs

5 issues
  • Inability to open/read certain file formats
  • Sync and account creation issues
  • Problems with PDF and image display
  • Crashes and compatibility problems
  • Duplication of books in library

Requested features

6 requests
  • Left alignment option
  • Dark mode/OLED black theme
  • Improved image handling
  • Better support for Chinese language
  • Vertical page flip
Show 1 more
  • Improved text-to-speech capabilities

Readest

Not enough reviews yet to summarise bugs or requests.

In-app purchases

4 purchases

KyBook 3 Ebook Reader

Subscriptions2
  • 3 months subscription7 Days trial$4.493 Months
  • Yearly subscription7 Days trial$14.991 Year
One-time2
  • Upgrade to Pro (Discount)$2.99
  • Upgrade to Pro$4.99
9 purchases

Readest

Subscriptions4
  • Subscribe to Plus Plan$4.991 Month
  • Subscribe to Pro Plan$9.991 Month
  • Subscribe to Plus Plan$49.991 Year
Show 1 more
  • Subscribe to Pro Plan$99.991 Year
One-time5
  • 1 GB$9.99
  • 2 GB$14.99
  • Full Customization$19.99
Show 2 more
  • 5 GB$29.99
  • 10 GB$49.99

Questions

Is KyBook 3 Ebook Reader free?
KyBook 3 Ebook Reader is free to download, with in-app purchases available.
Is Readest free?
Readest is free to download, with in-app purchases available.
Which has better reviews, KyBook 3 Ebook Reader or Readest?
KyBook 3 Ebook Reader is rated higher. KyBook 3 Ebook Reader averages 4.7 out of 5 from 4.7K ratings, while Readest averages 4.5 from 195 ratings.
Do KyBook 3 Ebook Reader or Readest have ads?
Neither KyBook 3 Ebook Reader nor Readest shows ads.
Which is updated more often, KyBook 3 Ebook Reader or Readest?
KyBook 3 Ebook Reader ships an update every 5 days, and Readest fortnightly. Most recently, KyBook 3 Ebook Reader was updated on October 23, 2026 and Readest on October 22, 2026.

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