Corrections, corrigendums, and retractions are only useful if you see them.
How about if Paperpile were to check for those when you load a PDF of a paper. Is that possible? Could it send a quick query to the journal website to see if any has been posted and bring it to your attention if one has?
It would help ensure that these sort of things are brought to your attention now, rather than some reviewer pointing it out later!
Likewise, I would be interested in knowing whether the reviews / reviewers of a piece are public (publons), or someone post-peer-reviewed (pubpeer, possibly hypothes_is). Would have to be minimal not to distract too much.
The corrections/corrigendum/retraction alarm is clearly something useful and it’s definitely possible to integrate services like http://www.crossref.org/crossmark/ to check for these document events. But it’s not something on our roadmap at the moment.
Also we don’t have plans to integrate with pubpeer or hypthesis_is. It’s not possible to integrate with all niche services out there and we need to be very selective. We also don’t integrate with much more popular services like Altmetrics.
What about Arxiv? Articles uploaded there are frequently modified and updated. I am starting to be a bit worried that my stored Arxiv articles are out of date. Would be excellent if there was an option to auto-download updates for Arxiv papers.