Astrid is a to-do list and task tracking system for iOS, Android, and the web. The Astrid API features a RESTful interface for interacting with data from the Astrid servers, including updating and retrieving data. Results can be returned in JSON or XML format.
Any mobile app that does anything interesting has an API. Yet most of the apps that help you get interesting things done do not expose that API to developers. For many of us, a to-do lists are the arteries of our work-life. Some popular task apps that could be integrating the disparate parts of our lives are instead maintaining silos of task data.