1. In a user equipment device (UE) configured for operating in wireless communication networks, a method comprising: monitoring operational state data of the UE during times when the UE is operating in a wireless communication network of a home service provider and during other times when the UE is roaming in a wireless communication network of a different service provider, the operational state data including: location, time of day, roaming status, and communication activity status; applying the monitored operational state data to a roaming prediction model configured for predicting future roaming state, wherein roaming state comprises: roaming, not roaming, transition to roaming, and transition to not roaming; monitoring communication behavior data of one or more application programs executing on the UE, the communication behavior data including: type of wireless communications engaged in by the one or more application programs, type of data transferred during wireless communications engaged in by the one or more application programs, amount of data transferred during wireless communications engaged in by the one or more application programs, duration of wireless communications engaged in by the one or more application programs, time of day, and location; applying the communication behavior data to an application-communication prediction model configured for predicting future communication behavior of the one or more applications, wherein communication behavior of the one or more applications comprises: scheduling communications with a network-based server, engaging in communications with a network-based server, and initiating communications with a network-based server; and based on the roaming prediction model and the application-communication prediction model, controlling communication behavior of at least one of the one or more application programs.