MuPDF Mini Viewer is a minimalist Android app that uses the MuPDF library to view PDF, XPS, CBZ, unprotected EPUB, and FB2 documents.
This is a minimalist version of the MuPDF app, which focuses on reading only. It does not support editing annotations or filling out forms.
The app will start with a file picker showing the contents of the external storage directory. Only files that it can open will be listed.
Each document you open will start its own activity, so you can view many documents at once. Use the Overview system button to switch between the file picker and any open documents and other activities you have running.
Tapping on the left and right side of the screen will flip to the previous and next pages. Tapping in the middle will bring up or hide the tool bars. A long tap will toggle highlighting of links. When the links are highlighted they are also active and tappable.
You can pinch to zoom in. When zoomed in, tapping will scroll to advance the next screenful of content.
In the toolbar there is a button to show the table of contents, if the document has one. In EPUB and FB2 documents, there is also a menu item to pick the font size. The scrubber at the bottom allows you to quickly jump to a given page in the document.