The SmartPhonebook provides information for the phone numbers that have changed the mobile operator, on witch operator are they. In the past users were able to detect mobile provider by the mobile number prefix, but since users are allowed to change their provider but keep the phone number it is impossible to know which phone number on which operator is subscribed now. But now there is an open database with this information by http://www.otvorenipodatoci.gov.mk/. This application uses this data to provide information about the mobile provider.