For Android Phones and Tablets
2016-01-01: NOTE: TiskTasks started out as a small side project in 2011 as one of the first Android apps for Todoist. Since then, Todoist has released an official app that is prettier, better supported and fully featured. Because of this, TiskTasks has been pulled from the Android and Amazon app stores. It remains here as an open-source project for educational purposes.
TiskTasks for Todoist is a free, open-source app that connects you to your todoist.com account. It beautifully displays and lets you interact with all of your Projects and Tasks.
Features:
TiskTasks works with all devices running Android 2.2+ and can be installed on your SD card.
The project is no longer being developed, but you can look at the source code if you wish.