1. A wireless end-user device comprising: one or more wireless modems to communicate Internet data with at least a first wireless access network; a non-transitory memory to store service policy data comprising first application credential information, associated respectively with a first device application, and first device agent instructions, associated respectively with the first application credential information; and one or more device agents configured to receive the first application credential information and at least a portion of the first device agent instructions from a network element reachable via one or more of the wireless modems, communicate with a network element reachable via one or more of the wireless modems to perform an application credential check for the first device application, and based on the application credential check indicating a correct correspondence between the first device application and the first application credential information, apply the at least a portion of the first device agent instructions to an attempted or actual use of the first wireless access network for Internet data communication by the first device application.