EBookDroid is an open source (GPL'ed) document viewer for Android based on the VuDroid code base.


Orion Viewer is described as 'Orion is a pdf, djvu, xps and cbz file viewer for Android devices, based on mupdf and DjVuLibre libraries' and is a PDF Reader in the office & productivity category. There are more than 25 alternatives to Orion Viewer for a variety of platforms, including Windows, Android, Mac, Android Tablet and Linux apps. The best Orion Viewer alternative is Foxit PDF Reader. It's not free, so if you're looking for a free alternative, you could try Foxit PDF Reader or MuPDF. Other great apps like Orion Viewer are Adobe Acrobat Reader, MJ PDF Reader, Xodo and Document Viewer.
EBookDroid is an open source (GPL'ed) document viewer for Android based on the VuDroid code base.


Comic Book Reader is the viewer you need to enjoy all your electronic publication. It is available both as Desktop and Windows 8 Metro UI for PC and tablets.




Offers viewing, searching, printing, and text copying for PDF files on Android. Streamlined for quick access and on-the-go use, optimized for work environments without Drive integration, lightweight, free, and requires minimal permissions.




PDFChef enhances document management with cross-platform support on PC, Mac, iOS, and browsers. It offers text-editing, page rearranging, conversion tools, and cloud-based sharing. Supporting various file formats, it also enables users to add signatures directly to PDFs for swift document finalization.




AI powered productivity tool for reading, understanding and taking notes on PDFs and long websites. Users can search, summarise, extract and define keywords, ask google-search type questions and be taken straight to the answers.




Genei is the most popular SaaS alternative to Orion Viewer.
Xpdf is a free PDF viewer and toolkit, including a text extractor, image converter, HTML converter, and more. Most of the tools are available as open source.







PDF X is a productive PDF reader & editor for Windows. It's powerful for users to view, print, edit, and annotate Adobe Acrobat PDFs.




Shelf is a convergent document viewer that supports PDF and EPUB files. With Shelf, you can organize your document collection by creating tags, like other Maui applications.



Take control of the way your ePubs display. Hyphen comes packed with a ton of options for custom colors, fonts, font sizes, line heights, paragraph indentations, margins - ...well, you get the idea. You can even use styling on a per-book basis.



