After a claim of copyright infringement on iReal Book I have after much consideration and careful weighing of several possibilities, come to the conclusion that the only expedient solution from here is to alter the app and to rebrand it.

I will still maintain the integrity of the original app and fundamentally disagree with the statements of copyright infringements as chord progressions cannot be copyrighted, however, after legal counsel and further deliberation have come to realise that challenging the matter would be financially crippling to an individual developer such as myself and further, the app would be missing from the store for a very long time which would be bad for all the people who need it for their studies.

The app in its new incarnation is now called iReal b (b as the flat symbol or as in book, band, better, blues, ...)
iReal b is now available for both iOS and for Mac.

For existing users of iReal Book, the new app iReal b is merely an update. As usual, everything should stay where it is ... with the new features added. They should still backup before and after updates.
iReal Book 3.0.4 will not backup the internal library but only your user songs. After having updated to iReal b 4.0 you'll be able to backup the whole library.
For both existing and new users this email backup is also useful to share whole libraries with other users.

For new users iReal b will not include any song, only 50 exercises for practicing of common chord progressions, so to obtain collections of standards one further step is needed to import them form a friend or from here in the forums. That is easily done by tapping on any of the playlists while viewing the forums on your iOS device (with iReal b installed).

The play along feature has been extended to include an new in-app purchase of 10 Pop styles.
The basic version of the app now includes three styles for the player (Medium Jazz, Bossa Nova and Rock) as opposed to before when only one was included.

Other new features include:
- Changed: iReal b includes 50 exercise chord progressions.
- Added: Export audio as WAV and AAC (requires iOS 4).
- Added: Loop a selection of bars of a chart for focused practicing.
- Added: Support for AirPrint (requires iOS 4.2).
- Added: In-App Purchase of Pop Styles Pack with 10 styles included.
- Added: Number system notation - Nashville notation (for individual songs or as global setting).
- Added: Setting (Background Audio) for compatibility with iRig/AmpliTube and other guitar connection kits.
- Fixed: playback position marker lag on older devices.
- Compatible with iOS 4.3