doo - A smart, simple app for reminders and to-dos
Mendeley - Easily organize your papers, read & annotate your PDFs, collaborate in private or open groups, and securely access your research from everywhere.
Purp - A smart to-do list and goal tracker app
Zotero - Zotero is a free, easy-to-use tool to help you collect, organize, cite, and share research.
Gone - An ephemeral to-do list
EndNote - Accelerate Your Research. Save time, stay organized, collaborate with colleagues and get published with EndNote 20.