Source code
Plain PDF is free software under the GNU General Public License, version 3. The full source code is published together with the first release on Google Play, and this page will link to it from that day on. Anyone who copies the app must keep it just as open, and that is the point.
Until then, questions about the code are welcome at support@plainpdf.app.
Plain PDF was made to be passed along. Fix something, translate it, put it on the phone of someone who is tired of ads, and whoever comes after you receives the same freedom you did. Good tools grow the way neighbourhoods do: one person looking after the next.