What are some alternatives?
When comparing jdotxt and Todoist, you can also consider the following products
Todo.txt - Track your tasks and projects in a plain text file, todo.txt. A todo.
Trello - Infinitely flexible. Incredibly easy to use. Great mobile apps. It's free. Trello keeps track of everything, from the big picture to the minute details.
Amazing Marvin - Customizable task manager and day planner
Asana - Asana project management is an effort to re-imagine how we work together, through modern productivity software. Fast and versatile, Asana helps individuals and groups get more done.
Nozbe - Nozbe - to-do, task, project and time management productivity gtd getting things done online application with software for Apple iPhone iPad Android Mac Windows Linux
Remember The Milk - Remember The Milk is a task and time management application for mobile devices.