CallMeBack App uses the latest , most-used and well-known USSD codes around the world providing you a fast , reliable and simplistic environment to send those messages faster than ever. CallMeBack Features: Total Number of Countries Supported: 36 Total Carriers Supported: 63 - Albania (Vodafone) - Australia (Telstra) - Bangladesh (AirTel,Grameenphone,Banglalink) - Belarus (Life :) ) - Bulgaria (Telenor) - Belgium (Proximus) - Cameroon (Orange) - Cyprus ( Cyta , MTN , PrimeTel , CallSat) - Doc