Read Up is described as 'read-up.io is an online epub and pdf reader. Allow you to read books, sync them all over your devices, and ask the community to share books you're looking for' and is a PDF Reader in the News & Books category. There are more than 50 alternatives to Read Up, not only websites but also apps for a variety of platforms, including Android, iPhone, iPad and Android Tablet. The best alternative is calibre, which is both free and Open Source. Other great sites and apps similar to Read Up are Project Gutenberg (Free), Amazon Kindle (Free), FBReader (Freemium) and Moon+ Reader (Freemium).
Calibre is a free and open source e-book library management application made by users, for users. Many languages, designed around the concept of the logical book, i.e., a single entry in your library that may correspond to actual e-book files in several formats.
Project Gutenberg is a library of over 60,000 free eBooks. Choose among free epub and Kindle eBooks, download them or read them online. You will find the world's great literature here, with focus on older works for which U.S. copyright has expired.
Amazon Kindle software lets you read ebooks on your Kindle, iPhone, iPad, PC, Mac, BlackBerry, and Android-based device. You can discover and read over 630,000 books in the Kindle Store, including the latest bestsellers and new releases.
Google Play Books lets you search, preview, and buy millions of books using Google Book Search. Books in the public domain and certain copyrighted books can be read and downloaded in their entirety for free.
Read book files in EPUB, PDF, DOC, DOCX, RTF, TXT, DJVU, FB2, MOBI and CHM formats. Supports chapters, bookmarks, page style. Saves the current reading position. Automatic detection and display of the list of all supported documents on your device.
Apple Books is the single destination for all the books you love, and the ones you’re about to. Browse the Book Store, join Oprah’s new Book Club, keep track of what you’ve read and want to read, and listen to enthralling audiobooks. All in one place.