This APP for making IDD call and need credit getting from prepaid voucher that is available in Singapore's retailer and/or reseller establishment. App will show credit balance and expiry date of the credit that charge with prepaid voucher. You can top up the credit and extend the expiry with a new valid prepaid voucher. User need to have Singapore mobile number to register as our user to use the app with credit in the app account. A SMS will send to user Singapore mobile number to verify the user mobile number by enter the verification from SMS before activate the app for making the call. Another condition is the mobile phone number must have valid credit either by credit link to mobile number or enter new prepaid voucher PIN via app at user registration stage.