LibriVox Audio Books Supporter - LibriVox Audio Books Supporter app comes up with an extensive collection of audiobooks through which you can search for your favorite book and listen to it in your native language right at your fingertips.
Okular - Okular is a universal document viewer based developed by KDE.
Speechy - Speechy is an app by Twelve Stars Software that comes up with features to help you in reading text in a variety of different formats such as pdf, txt, EPUB, webpages, and many others.
Sumatra PDF - Sumatra PDF is a slim PDF/DjVu/EPUB/XPS/CHM/CBR/CBZ/MOBI viewer for Windows.
Pocket Notebook - Pocket Notebook is an app by Wolters Kluwer Health LRP that comes up with features through which medical students can clear all their doubts about medical terms right on their mobile phone screen.
Foxit Reader - Foxit Reader is a free and light-weight multi-platform PDF document viewer.