Wunderlist is a beautifully designed and simple to use to-do / task app you can use on multiple platforms including Android, iOS and Mac OSX. It is free for everyone, you can unlock additional features with a Pro-plan.
Pro Can add to your list via email or Google Now
If you're on the run or away from your device, you can add items to your list by email. You can also add notes to the list item using the body of the message. Wunderlist supports Google Now, meaning you can add to your list using native voice commands on Android.
Pro Beautiful backgrounds
Wunderlist comes with 20 free wallpapers and 10 paid wallpapers for users to customize the background image in the Wunderlist app. In addition, advanced users can also use their own image as background image with few tweaks, which is absent in main Wunderlist app.
Pro Simple, useful task management features
Wunderlist features the standard ability to add tasks and organize them within lists, but one aspect in which it excels is the amount of detail you can add to each task. Rather than simple alerts, tasks incorporate a number of other options, including reminders, subtasks, notes, and recurring tasks. You can also star important tasks, which is simpler than the priority systems used in many other apps.