The best for me would be an opensource mobile-compliant PDF reader that nicely reflows the text of scientific PDFs for small screens... But I'm aware this is very challenging ;-)

Thank you anyway for opensourcing!

Not sure if these are supported already (just skimmed over the website and the list you've put here), but these are things I've wanted for while reading papers:

• Dark mode. Viewing white PDFs before bed is unpleasant.
• A way to view two-column papers as a single column (putting the right column below the left column?) so that I don't have to keep moving around

Those are probably the two things that bother me the most. In terms of exciting future work and keeping with the theme, you could also consider doing some automatic summarisation of text / papers (especially for citations), but that's much less necessary.

Looks dope! I’ll give it a download and try it out next week or so.

Show if the reference really says what the paper says it says.
Show if claims are disputed elsewhere.
Identify plagiarism or likely use of AI.
Jump internally to referenced statements or sections.
Open supplements in a side panel or tab.
Zoom to figures in full screen.
Link to grant funding info.
Similar articles search.
Quick word definitions.

This looks pretty cool... but I think it would need touch support for me to want to use it though in place of just Drawboard, or even Edge.