Systems, methods, and computer program products to perform an operation comprising executing a first application on a mobile device, identifying a first user in proximity to the mobile device based on a predefined proximity criterion, and responsive to identifying the first person in proximity to the mobile device, identifying, in a registry, a first action defined on the basis of a predefined association between the first application and the first user, and performing the first action to modify at least one of the mobile device and the first application.