List of research paper meta information sites Note: So-called "big-list" questions are occasionally tolerated here; I'm hoping this one will pass muster.

I'm looking to compile a list of existing post-publication meta-sites.  These would be sites that list research papers (as does any online publication), but instead of just linking to content, they list meta information about the articles.

Most online publications (eg, PsychNET) and search engines (eg, Google Scholar) already list a variety of common meta-information, such as: Abstract, authors, journal, date of publication, citations, etc.  I'm not interested in meta-information already provided by authors upon submission, unless that information is listed on the site in a normalized, searchable format (eg, with a query API).

Rather, I'm looking for meta-information that requires analysis (typically involving human intervention) to compile.  Examples might be: The list of experiments, the "n" of each experiment, the results and significance (p-values), the type of each experiment (RCT, blindness, population study, pre-registered, etc), research field search tags, responses and replications, meta-analyses that the paper is included in...

Examples that I'm aware of to get this list started:


ShortScience.org: Lists layman abstracts for AI papers.
scite_: Check if papers have been supported or contradicted. 


What else is out there?
Very interesting question! I would mention https://www.semanticscholar.org/, they do something similar to scite. They classify citations into e.g. "Cites Results" or "Cites Background", they describe their method in this paper.