The described embodiments concern one or more methods, systems, apparatuses, and computer readable mediums storing processor-executable process steps to authenticate mobile subscribers for using a foreign application when they are outside of their home telecom carrier's mobile network zone (“foreign zone”). A mobile subscriber can be authenticated through data roaming service, voice roaming service, and/or WiFi service. After cross network authentication, a mobile subscriber can use the foreign application to provide the same or similar services in a foreign zone, such as foreign country, through the home services in connection with the subscriber's home telecom carrier in a similar manner like he/she can use in his/her home zone, such as home country.