I have released version 5.0 to the appstore. This should be available in a few days after review. The improvement in this version includes auto tagging. If your source files already contain metadata such as book title, author, comment or artwork then Audiobook Wizard will automatically use them in the final audiobook output (The first file encountered with metadata will be used as the metadata source). The build process has become even simpler. You could literally drop in files and start building immediately.
There are also a couple of bug fixes for random crash when user click on cancel while building a book.
I feel Audiobook Wizard is as complete as it can be for most users in this form but I am always willing to hear from people that love to read. Contact me if you have improvement suggestions etc. Have a nice day!