How to run USSD commands on android?

has anyone know how to runs USSD command for checking phone's credit balance (the number is *123#) and get the result (the credit balance) for further processing?

You can run USSD codes in Android devices but you would be unable to parse the result in your application. This feature might be added to the Android SDK in the future but for now, you would have to look for an alternative.

USSD can be run using simple Call intents. See Example:

String ussdCode = "*" + "123" + Uri.encode("#");
startActivity(new Intent("android.intent.action.CALL", Uri.parse("tel:" + ussdCode)));