calibre - Ebook manager, viewer & converter
DealOz.com - Save time. Save money. Discover. Search new and used books, textbooks, and ebooks using the most trusted shopping comparison site, DealOz.com.
Apple Books - The all-new Apple Books has been redesigned to make finding, reading, and listening to books a beautiful, effortless experience on iPhone and iPad.
AbeBooks - AbeBooks has millions of new & used books, rare books and out of print books.
Open Library - The ultimate goal of the Open Library is to make all the published works of humankind available to...
Neat Reader - If you’re looking for a free and easy-to-use online EPub reader that works seamlessly on all your devices, consider Neat Reader. You can use it for free across all devices. To use it on your browser, simply Open Web App.