The Ontimenow Scrum API is an Agile management tool with REST calls and JSON responses, and uses Oauth2 authentication. The API allows calls to check contacts, view defects, check features, tasks, incidents, projects, releases and users.
The newest version of the Google Drive API should help developers more easily add Drive to their own apps. Google says the improved API is more consistent and simpler for first-time developers. Drive within apps can be used for file storage in addition to creating and editing files.