Alfa Ebooks Manager contains built-in ebook reader that allows you to read or preview books. It supports the following book types: PDF, EPUB, MOBI, FB2, CHM, HTML, TXT and comic books (CBR, CBZ).
In order to activate the reader, you need to check the box "Use internal reader" in menu Tools -> Options. If this box isn't checked, ebooks will be opened in program, that is set as default for this file type in your system.
Besides, in Settings you can set to open ebook files by double-clicking on a book in Alfa's library. Otherwise books are opened using the right-click menu.
Ebook reader remembers the page where you last finished reading each book. You can open multiple reader windows at once. You can also customize different text styles and options.