Disclosed is a system for downloading an application from a server and providing the same to a client by using a short message or a subscriber interface module (SIM) card. The system modifies a function key for each application according to a client's selection, and randomly modifies a user interface used for selecting an application. The system extends a usage range of the SIM card. The system periodically checks and analyzes the client' use log for a predetermined time, presents at least one application to the client according to the analysis result on the use log, provides a single application selected by the client to the client, and updates at least one application stored in the client mobile terminal according to the analysis result on the use log. Therefore, the system increases service satisfaction for the client.