ToDoIst and its sister service WeDoIst are task management tools that I've covered a couple of times in the past. Most recently I included them in this list of group project management tools for students. Today, ToDoIst and WeDoIst released an update that enables users to manage their task lists online and offline. Now users can manage their task lists even without an Internet connection and when they reconnect to the web their changes are synched to their accounts.
Applications for Education
The user interface of one task management tool might appeal to one person while not appealing at all to another. It is for that reason that I like to provide my students with a list of task management tools to try. That said, what I like about Todoist is that it provides a variety of ways for students to access their to-do lists through the web, with desktop clients, and through mobile devices.