I've been using Acrobat reader on my Android tablet to read choir scores during rehearsals and concerts for the past few months.

It works okayish, but Acrobat being the proprietary shit that it is, not great.
- It constantly tries to upsell me to their propriety cloud service (f*** off);
- it has various buttons in the interface (such as the blasted 'liquid mode') that I keep accidentally tripping while trying to sing which changes the way page changes work;

- It allows me to squiggle notes on the page, but it tries to 'improve' the notes and markings that I draw on the page with my stylus, making the handwritten notes unreadable (e.g., by turning what was meant to be a quickly written 3 into a reverse C, because you clearly didn't want to have that extra curve in there 🙄)
- it doesn't provide an eraser, requiring me to remove a whole marking and redraw the bits that I did still need

- It doesn't do the thing that allows an Android app to keep the screen on, resulting in my tablet more often than not switching off in the middle of a song, resulting in me being panicked while I quickly enter the pin code to unlock it again.

So.

Does anyone know of a PDF reader app for Android (preferably available through F-Droid) that:
- lets me read my scores
- lets me take notes on said scores

- does not try to 'fix' or 'improve' my handwritten notes but keeps everything as drawn
- has an eraser function for these notes
- lets me keep the tablet unlocked while active

?

If you do, I'll owe you a favour.

Thanks!

@ArnimRanthoron
Mmmm. Not quite sure yet I want to go to another proprietary option, but other than that, looks like a better solution than Acrobat, indeed.