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.