[skepdimi]

If you download the PDF, you can annotate PDFs locally. Why not do it that way?

[loltyler1]

It's about the crowd-sourcing aspect of genius.com.

Experts in the various fields could annotate papers in order to make it easier for non-science-savvy people to get what is going on.

[skepdimi]

This is an interesting idea. I think the problem with such an app is that reviewers and publishers have sort of a monopoly on papers, which makes it hard from a business perspective