Todoist - Todoist is a to-do list that helps you get organized, at work and in life.

Taskful - Deadlines, meet your match.

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

Calendarist - Time blocking companion for Google Calendar

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

Gone - An ephemeral to-do list