calibre - Ebook manager, viewer & converter
Kingshiper MP3 Converter - Kingshiper MP3 Converter is a reliable and easy-to-use tool to convert your music files into MP3 format in seconds.
FBReader - FBReader is an e-book reader for various platforms. Features:
OpenAudible - OpenAudible Project Page
Google Play Books - Google Play Books lets you search, preview, and buy millions of books using Google Book Search.
Sidify Apple Music Converter - Sidify Apple Music Converter is a popular tool used to convert Apple Music, iTunes M4P music and audiobooks to MP3/AAC/WAV/FLAC/AIFF/ALAC. It keeps lossless audio quality and ID3 tags after conversion.