1. A system for managing behavior change applications receiving data associated with a plurality of users operating a plurality of devices in a communications network and delivering interventions to the plurality of users, the system comprising: one or more servers computers including application programs which when executed cause the one or more servers computers to control the system to: receive a first data set from a plurality of applications, each of the plurality of applications implemented on one of the plurality of devices and collecting data associated with one of the plurality of users for the first data set, wherein the first data set includes activity information of the plurality of users and user attributes of the plurality of users; determine a plurality of user segments for a behavioral change program based on the received first data set, the plurality of user segments each including a subset of the plurality of first users; determine a second data set, the second data set being a subset of the first data set and associated with a selected user segment of the plurality of user segments; determine a behavioral model for the selected user segment, the behavioral model comprising a statistical model of relations based on the second data set; receive a third data set from a selected application of the plurality of applications that is associated with a selected user and a selected device, wherein the third data set includes activity information of the selected user and user attributes of the selected user; classify the selected user into the selected user segment of the plurality of user segments based on the third data set; determine an intervention model for the selected user based on the behavior model for the selected user segment, and, send an intervention to the selected application according to the intervention model, wherein the intervention comprises a notification perceptible at the selected device and the intervention is sent to change behavior indicated by the activity information of the selected user.