Mendeley - Easily organize your papers, read & annotate your PDFs, collaborate in private or open groups, and securely access your research from everywhere.
Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
JabRef - Graphical Java application for managing bibtex (. bib) databases.JabRef · JabRef Help · JabRef | Blog · OpenOffice/LibreOffice .
Zotero - Zotero is a free, easy-to-use tool to help you collect, organize, cite, and share research.
Citavi - Citavi is a program for Microsoft Windows that manages literary references and organizes organizational knowledge.
EndNote - Accelerate Your Research. Save time, stay organized, collaborate with colleagues and get published with EndNote 20.