Astrid Task/To Do List
No other app gives as much detail to to do lists as Astrid. Its "advanced" options lets you set priority levels, integrate with Google Calendar, sync with Google tasks, and set up tags, alerts and periodic reminders. Astrid keeps it easy, for the most part, but also offers deeper settings if you're the obsessive, customize-everything exactly-how-you-want-it type. If you use Remember The Milke or Producteev, Astrid can sync with them too (though it's not necessary). The app isn't the prettiest but it doesn't over complicate things. Spring for the Power Pack ($3.99) to unlock voice features and some better widgets. Free, Android. $4 for Power Pack.
Got To Do
One of the more thoughtfully designed Android apps, Got To Do has a great "homescreen" interface (that's customizable) and syncs with the Toodledo webapp (for more features). On top of that, Got To Do has a nice widget, gives options for task templates, and uses subtasks (if you want to break down bigger tasks). It doesn't throw as many setting tweaks to to do lists as Astrid but by keeping things simple, it's just as nice to use. Free, Android.$3.11 for Pro.
gTasks
If you're a big user of Google Tasks, gTasks is the perfect app. It maintains the simplicity of Google Tasks by automatically syncing tasks on gTasks with your Gmail account. There's a widget, reminders, sharing options and a nice-because-it's-simple layout. In fact, gTasks is organized just like your Google Tasks. Free, Android. $7 to remove ads.
OTHERS TESTED:
• Remember The Milk: If you're a big RTM user, you'll have to have the Android app. Too bad RTM services (location based alerts, smart lists) cost $25/year
• Checkmark ToDo list: Really gorgeous interface that sometimes buries what you need to do
• TooDo: Ridiculously full featured but needlessly complicated. If you're insane about having perfect settings though, TooDo offers smart folders, geo-notification settings and tons more.
• Taskos: Use your voice to save to do lists
• Google Task Organizer: Another dead simple Google Tasks app
• OI Shopping List: Good for the supermarket.
Fuente: http://gizmodo.com/5707232/the-six-best-apps-for-getting-stuff-done