Requires iPhone or iPad GSM
iPhone 4S and iPad 3 is Not supported by this tweak
Perform USSD (Unstructured Supplementary Service Data) queries on iPhone/iPad GSM.
This queries can be used to check the credit of prepaid sim cards or the remaining inclusive service.
No new icons are added to your home screen. You can configure the USSD code of your mobile operator and the activation method using the settings app. The query response is displayed in a popup message.
(Queries are normally free of charge however there may be mobile operators that charge you.)
See the Screenshots below