17. A system, comprising: memory; one or more processors; a virtual sensor stored on the memory and executable by the one or more processors to implement inference models that accept physical sensor data from a plurality of mobile devices and to output inferences regarding phenomena to an application, the inferences based on the physical sensor data; and a decision engine configured to select a subset of the plurality of mobile devices and to upload time intervals to provide the physical sensor data based on a value of information of obtaining additional physical sensor data and temporal and location-based constraints placed on the upload of physical sensor data.
20. The system of claim 17 , wherein an instance of the application is executable by a one of the plurality of mobile devices that is not part of the subset of the plurality of mobile devices.