Orion Viewer - Pdf & Djvu is a free and open-source application that allows users to view pdf, djvu, xps, cbz, and tiff files on their Android devices. The program is developed by Michael Bogdanov and falls under the Education & Reference category, specifically under Books.

The application features a range of tools that make reading and navigating through documents easy and convenient. Users can navigate through the pages of a document with screen taps, tap zones, and key binding. Additionally, the app supports outline navigation, bookmarks, custom zoom, and portrait/landscape orientation.

One of the most convenient features of Orion Viewer is the single-word selection with translation in an external dictionary. The app also supports custom manual and auto border crop, different navigation patterns inside a page (left to right, right to left), and external dictionaries.

Moreover, Orion Viewer comes with a built-in file manager that displays recently opened files. The application is free and open-source, licensed under GPL. Users can donate to the project by purchasing Orion Viewer: Donation 1$, 3$, or 5$ package from the market.