The subject disclosure pertains to systems and methods for providing an improved user interface for mobile devices. A user interface can obtain content including data and associated tasks from a set of software applications. Consequently, users can access content from multiple applications without navigating away from the user interface. The system architecture is extensible, providing for the addition of applications and user interfaces without requiring modification of the existing applications or user interfaces. Applications can register data suppliers capable of retrieving data from the underlying data store for the application and task executors capable of acting on the data. A user interface can generate a query requesting a class of data and specifying a context used to filter possible results. The system can determine the appropriate data suppliers, distribute queries and return the assembled results to the user interface.