I've only learned about docracy from this post (which is a shame) but I've used https://dochub.com/ in the past and it works really well.

Not having used docracy I'm not sure if there's feature parity but it at least seems similar (e.g. editing & signing PDFs/documents)

edit: I see that one of the (if not _the_) feature of docracy was the shared library of documents/templates. That's something Dochub doesn't have I think.