A simple sync mechanism would keep paper libraries identical across computers. Without this, one has to manage multiple paper libraries on different computers.

It would be very useful to have a preferences page with a list of folders that should be automatically monitored for new PDF documents that could be imported into the library.

Sync should be doable via a connection cable as well as via wi-fi.

Built-in citation management, bibliography generation, and integration with word processing. "write and cite"

ReadCube runs on Linux (in addition to Mac OS and Windows)

ReadCube could be very useful on android tablets.

Like iTunes, copy, rename, and sort all existing and newly imported PDF files into a folder system.

This would include a file renaming scheme so that PDFs aren't all named "fulltext1.pdf"

Allowing users to specify the default folder where newly imported papers are stored would give users better control over their computer files/directories and backup schemes.

A full screen view would get rid of the side panels and to improve the reading ease.

highlights and /or notes could be saved on the PDF with the option of printing with or without. I would also recommend the feature allow you to choose to print with highlights or notes separately

More like a folder tree than a tagging system because some users have distinct projects and subcategories within those projects.

Scopus, for example, or arxiv (physics and math)

To allow ReadCube to manage items like patents, book chapters, personal protocols, and notes.

As of now, I have not found a way to tell the software to check all the unmatched files, once they are initially imported. I can identify most of them automatically individually but this is hardly useful when you have 3000+ papers...

When I added PDF documents to readcube, I realized that the papers which I read before and highlighted do not contain previous remarks. It might be useful as well if you improve readcube to import highlighted documents. So, I can use that document with readcube and also continue reading.

The recommendations found an article that I would like to send to a friend... it would be great if I could simply send him a link to it (pubmed or journal), or a PDF

Staging papers over and over again when trying a new reference manager is a real pain. It would be an advantage for ReadCube to allow its users to import the groups and lists they have already created to directly have their library organised.

It's nice to have some kind of plugin, so when you are searching for papers in Pubmed in Firefox (or whatever browser you use) you can import them into ReadCube. In this last feature it would be best if you can import a whole clipboard.

I'd love it if ReadCube could list newly released eTOC's for me, or provide a way that I could link from an eTOC directly into a ReadCube download. eTOCs (or journal online TOCs) are how I browse new literature, and it'd be really helpful it that were integrated.