An App for Office is basically a webpage that is hosted inside an Office application and can extend the functionality of a document or an attachment. Apps for Office combine cloud services with standard web technologies such as HTML5, AngularJS, CSS3, JavaScript, XML, and REST. These code samples provide the ability to integrate cloud storage services like Drop Box, Google Drive and OneDrive for both a task pane and mail app in the Office 2013 and Web App interfaces which also includes a Outlook app.