Todoist - Todoist is a to-do list that helps you get organized, at work and in life.
Focuster - Ditch your todo list for an intelligent scheduler
Todo Tab - A privacy-first todo list
Taskbook - Like Trello but for the Terminal
WaterDo - WaterDo is the most fun to-do list made by the team of《Forest》In the world of "WaterDo", your schedule become bouncy Water Balls.
Nirvana - Nirvana is a web-based GTD task manager.