Todo.txt - Future-proof task tracking in a file you control.

Apps that manage your personal todo.txt file at the command line, on Android & iOS. Dropbox built in. Todo.txt apps are minimal, todo.txt-focused editors which help you manage your tasks with as few keystrokes and taps possible.

There are great GUI apps for Todo.txt now, as well. Check out http://benrhughes.github.io/todo... on Windows. I keep the text file on Dropbox and have access to it from every device I own.