In some examples, a first mobile device is placed into communication with a second mobile device, such as through a short-range radio connection. User information is transferred from the first mobile device to the second mobile device. For example, application information for an application and saved application state information may be transferred to the second mobile device. The second mobile device may configure the application on the second mobile device based in part on the application state information received from the first mobile device. In addition, a user communication ID may be transferred from the first mobile device to the second mobile device, and may be used for communication with a third device with which the first mobile device has previously communicated. For instance, the user communication ID may be used in place of a device communication ID when sending communications from the second mobile device.