To-do lists of the past were scribbled in notebooks, on sticky notes, or on whiteboards. Today, they live in our smatphones. Or at least they should.
(http://cache.gawker.com/assets/images/gizmodo/2010/12/todolistszaz.jpg)
iOS
2Do
Toodledo
Remember the Milk
Android
Astrid Task/To Do List
Got To Do
gTasks
The Six Best Apps for Getting Shit Done [Appbattle] (http://gizmodo.com/5707232/the-six-best-apps-for-getting-stuff-done)