ReadCHM is a CHM ebook reader for the iPad, iPhone and iPod Touch.  (Click here to see some screenshots.)  

Features supported in ReadCHM 1.0
  • Read CHM files in any languages
  • Manage books in library via iTunes
  • Browse and search for sections
  • Search keywords in page
  • Customize font size, font type, line height, encoding etc.
Features supported in ReadCHM 2.0
  • Better performance and smoother user experience
  • Automatically land to the last reading section (can be turned off)
  • Bookmark a specific section of a book and browse to that section later
  • Navigate among in-page search results
  • Lookup selected words with Google or Wikipedia
  • Email a selected text
  • More realistic screen brightness effect
  • Animated loading indicator for long operations
Features supported in ReadCHM 3.0
  • Support iPhone and iPod Touch running iOS 4 or above

  • Support big files with large index size (we've tested with documents over 50MB and thousands of index entries)

  • Arrange table of contents in tree structure


  • Support Pinch Zoom enabling/disabling

Features supported in ReadCHM 4.0
  • Support iPhone and iPod Touch running iOS 3 or above
  • Allow users to turn on/off double-tap (to turn pages)
  • Drill-down search in table of contents
  • Allow users to turn on/off incremental search
  • Import CHM files Wi-Fi
  • Import CHM files via other applications such as Mail and DropBox
  • Non-Unicode books could now be read seamlessly without requiring user to change encoding
  • Support retina screen
Features supported in ReadCHM 4.1 (latest version)
  • Support AirPrint
  • Options to go back & forth
  • More code fonts
  • More iterations for font size and line height
  • Adjusted page margin
  • Several bug fixes
What's Next?
You can refer to the User Guide to learn how to use the application. 

Please report issue or request feature by sending email to readchm@gmail.com.  Make sure you add this address to the spam filter.

If you like ReadCHM, please write a short review for it in App Store.
ReadCHM makes use of a modified portion of the great open-source library Chmox led by Stéphane Boisson (which is, in turn, built on top of Jed Wing's CHMLib). The modified portion is released as a standalone library under LGPL license.  You can download the source of this library here.  You can modify this library, link and build it with ReadCHM's object files to create a combined version of your own.  ReadCHM's object files and build instructions are available for download here.