The news app consists of three distinct major layers (storage, business and data access, presentation). The storage, data access and business layers constitute a unified framework (the backend) that merges the various repositories and exposes them in a web services format following the business rules of the system. The presentation layer consists of as a set of end user applications (mobile UI, tablet UI, web front-end). The front end user interfaces exchange data with the backend by means of HTTP messages. For the facilitation of the development, the SocialSensor java-client SDK is used in certain cases internally by the client applications. More specifically, the news app web front-end is built in Java Server Faces web framework together with Primefaces, following a Model-View-Controller approach. A loosely coupled architecture is also followed on both the tablet and mobile app that are implemented in native objective-C for iOS 7, and communicate with the backend by HTTP calls to the exposed RESTful services.