Workflowy - A better way to organize your mind.

Todo.txt - Track your tasks and projects in a plain text file, todo.txt. A todo.

Checkvist - A professional list-making tool. Minimalist, keyboard-centric online outliner and task management application. Free sharing, unlimited lists, cross-linking, free import and export. Markdown support. Created for geeks 🤓 and all keyboard lovers ⌨️

Task Coach - Task Coach is a simple open source todo manager to keep track of personal tasks and todo lists.

OmniOutliner - OmniOutliner is a writing app for collecting information, outlining ideas, adding structure to any sort of writing.

Strikethru - Strikethru is a kind of to-do list notebook for managing work lists and staying updated with the important tasks.