Sigil - Sigil is a multi-platform WYSIWYG ebook editor. It is designed to edit books in ePub format.
Universal Book Reader - Just like its name, Universal Book Reader is really a universal book reading application allowing you to read the eBooks from the convenience of your smartphones.
Jutoh - Epub editor, convertor and creator software for Mac and PC.
Cool Reader - Fast and small cross-platform eBook reader for desktops and handheld devices
calibre - Ebook manager, viewer & converter
iReader - iReader is one of the most accomplished ways to read the books right from your smartphones.