Mendeley is a desktop and web program for managing and sharing research papers, discovering research data and collaborating online. Or to put it more simple: it is an academic social network.
Make your own fully searchable library in seconds, cite as you write, and read and annotate your PDFs on any device. This way you can easily organize all your academic papers and stay up-to-date in your field of research.
Mendeley is available either as a basic version that is free or a premium payable version.