Abstract: Methods and systems for user, activity and application profiling for a mobile device are provided. According to one embodiment, activity stream data is received by an activity monitoring module running on a mobile device. The activity stream data includes information regarding usage of one or more applications installed on the mobile device. The activity stream data is provided by the activity monitoring module to a central server that collects activity stream data from multiple mobile devices, including the mobile device. The collected activity stream data is processed by the central server in conjunction with auxiliary data to create derived mobile user activity profiles for users of the mobile devices.