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

Taskbook - Like Trello but for the Terminal

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

Todorant - Tricks yourself into craving completing tasks

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

vim-taskwarrior - a vim interface for taskwarrior