ReadCube Papers is a competitor with reference managers Endnote, Zotero, Mendeley, and RefWorks and has features of all of those for managing a library of citations, pdfs, searching for and sharing scholarly articles, and adding citations to manuscripts. This is an upgrade of Papers3.
Important points about Papers:
Access has been enabled for MSU's Web of Science subscription to work with Papers.
(Note: A glitch caused problems with Web of Science access through Papers2, but Papers 2.5.5 update for Mac restored the functionality.)
Documentation for how to use and access this service is available at: http://wokinfo.com//media/pdf/wsdownload/
User Name: wsl
Access has been enabled for MSU's Scopus subscription to work with Papers.
You may or may not need MSU Scopus Account ID for your Settings, depending on which version of Papers you are using. Newer versions do not require it.
MSU Scopus Account ID: 51676