The invention relates to a digital telecommunication system for the access, navigation, and use of digital applications and services, referred to as a USSD CENTRE (14), that comprises at least one server for applications and services module (16), at least one access gateway module (17), at least one network gateway module (18), at least one integration gateway module (15) and at least one database and profiling module (19). The server for applications and services module (16), referred to as a Browser (16), is based on at least one USSD telecommunication protocol and on at least one VXML language interpreter (21). The USSD CENTER (14) further includes charging, billing, proxy, routing, observation, ranking, and self-learning modules that execute the respective operations in real-time or offline. The USSD CENTER (14) further includes a WEB-type environment module for creating multilingual services, for test and for development of services and for managing the versions of the said services either locally or remotely. A method is implemented using the system (14), thus enabling a user to access USSD services via existing or new non-USSD services and enabling a user to access existing or new non-USSD services via USSD services.