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,
• 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

What’s New

Version v0.7.8

- Fixed the issue with clipped text in PDF Reflow.
- Added the ability to change text size in PDF Reflow mode.
- PDF page is rendered in the current theme when the PDF Reflow mode is on.
- The application now remembers the Reflow mode for the recent open PDF book.
- Various minor improvements and bugfixes.

Ratings and Reviews

4.6 out of 5
1.2K Ratings

1.2K Ratings

Thanks.......... ,

The Only Ebook App You Should Get!

I was surprised how distinguished this app was from it’s counterparts.
I only started using this app since it was the only one of ten other apps that allowed me to add books to it via 3uTools.
But once I started going through the features, I found that this app was much more than I expected it to be.
Dark-Mode was something that I thought was vital for readers, at least for those that read for hours, so I found it abhours that this seemed to be a feature that was either lacking or missing because you didn’t upgrade to “Pro” for $7/Month. That figure didn’t really exist, it’s rhetorical.
Long gone are the days when you used to do one-time fees and never worry about it again.
But not only can you pay a one-time fee in this app, the reason why I even bought it in the first place was because this app didn’t restrict any features just because you were a free user.
At least not any that stood out enough for me to not want to use the app anymore.
It had Dark-Mode and the ability to add your own fonts.
That’s all I expected Apple to add to iBooks but since it doesn’t seem like they’re moving off of the old iBooks from 2008, you have to find an app that has these features.
This app has everything that I need and even more features that I didn’t know I needed.
As long as this app offers a one-time purchase option (which was for options I don’t even use) then this app will always be above all the other Ebook apps out there.

NebraskaJer ,

Was a great app

Version 2 was great, awesome, unique and a must install. Now version 3 and not much has changed but a new pricing model. Why??!??? I paid lads than three months ago and would not mind to upgrade to version 3. Show me the benefits and what is better about. Why not have a discount for version 2 holders? Then on top of that you have a subscription mode? Why do you give me a pro “upgrade” model and then ask for subscription? Ugh. Did Adobe or Microsoft buy you or something. Another day another app that wants to jump on the SAAS model. Very unhappy. I guess I will convert all mobi and epub to pdf or just import into iBooks. Another app down the tube. What is the point of a “subscription” model for this? I understand making some money and keeping it updated so charge me a flat fee. I use it once a month or so, so I am not doing the rolling subscription. Uninstalling and keeping version 2 until a response is heard or you roll back on the decision. I have a cloud subscription for iCloud so why can’t I download and sync with that? I have all my ebooks there already and would love it to see your team utilize iCloud fully. Why get in the business of making a book storage server? Apple and Google can do it way better and cheaper. Please rethink this and stick to what you are good at. Creating a book reader. If this continues I hope Apple buys this app and rolls it into iBooks. Win-win for me. Thanks anyway.

Parsica ,

The best but with a couple of defects

I am a book lover and this is the best comprehensive app I’ve found in app store for reading and managing my library, but there are a couple of shortcomings that nags me; first with regard to pdf files the first kybook app (which is not updated any more) had a better pdf engine (or I suppose so) because one could magnify documents to a larger scale and this was very helpful in reading pdfs that were in double page format or the fonts are very tiny(very handy when you don’t have glasses around) and second if you import a book more than one copy (erroneously) and later need to delete extra copies all files are deleted and you cannot save the original copy so you have to keep all copies together (and waste some space) or delete all copies of the book and then import it it again once (if you have access to the book).
In the end I recommend you to buy the pro version because it’s very cheap compared to it’s capabilities.


Konstantin Bukreev
55.9 MB

Requires iOS 11.0 or later. Compatible with iPhone, iPad, and iPod touch.


English, Czech, Russian, Simplified Chinese, Spanish

Age Rating
Unrestricted Web Access
Infrequent/Mild Horror/Fear Themes
In-App Purchases
  1. Upgrade to Pro $4.99
  2. Upgrade to Pro (Discount) $2.99
  3. Yearly subscription $14.99


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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