Compare software

MJ PDF vs Orion Viewer: catalog facts
MJ PDF	Orion Viewer
Free Free and open source under the GPL 3.0 licence.	Free Free and open source under the GPL.
Android	Android
Library view with recent files, folders and reading history Dark mode for the PDF content as well as the interface	Opens DjVu as well as PDF, XPS, CBZ and TIFF Configurable tap zones and key bindings for page turning
Android only A reader with annotations rather than a full PDF editor	Viewer only, with no PDF editing Interface is functional rather than polished
Downloadable app	Downloadable app
Open source	Open source
License: GPL-3.0-only	License: GPL-3.0-or-later
No account needed	No account needed
Not stated if it works offline	Works offline
Official website Full listing and sources Checked October 2, 2026	Official website Full listing and sources Checked October 2, 2026

Catalog facts only. Anything “not stated” is unconfirmed. Check full listings for details.