Mendeley - Easily organize your papers, read & annotate your PDFs, collaborate in private or open groups, and securely access your research from everywhere.

Keeeb - Keeeb unleashes knowledge that the corporate enterprise didn't know it had. We connect existing information islands while optimizing the discovery process with a novel workflow, and automate knowledge discovery through artificial intelligence.

Zotero - Zotero is a free, easy-to-use tool to help you collect, organize, cite, and share research.

Getodo - colorful lightweight multi-level to-do list on Android, iOS, web.

Qiqqa - Qiqqa is a free research and reference management software. It can be used in many organizational projects from the academic to the personal to the business endeavor. Read more about Qiqqa.

Ping.it - With Ping.it you can manage the news and entertainment of the web all in one place.