Publishers are under increasing pressure to develop workflows that enable their assets to be published to mobile platforms such as the iPad and the Kindle. Many book publishers are already using a variety of methods to create eBooks and where these equivalent print products are very text heavy (such as trade fiction) then this is very appropriate. But under what circumstances would it be better to create an 'app' rather than an eBook?
BBEdit version 10 has the ability to open the contents of an ePUB file. You can edit the individual components of the ePUB - which, of course is actually a ZIPped file, and then re-save.
But does this actually work without issues?