USSD-SA is a mobile application that provides an intuitive human-machine interface to subscribers of all telephone networks in South Africa(Vodacom, MTN, Cell C, Telkom). It allows access to all USSD services available on a particular network without requiring any special memory effort from the users. With USSD-SA, a user is able request a Callback from another contact with respect to the given network by just clicking on a button and picking the contact from his phone book.
Below is a list of some of the services you can perform on MTN using this app:
-Check your airtime balance
-Purchase a data bundle
-Access MTN master menu
-Data bundle cancellation
-Detailed balance inquiry
-International calling rates
-Call diverting
-Please call me back
-MTN easy recharge
-MTN Me4U
-MTN Me2U
-MTN pay4Me
-MTN service
-Recharge via Absa
-Price plan migration
-SMS bundle purchase
-SMS bundle cancellation
-SMS roaming

With Vodacom, you can perform the following services:
-Access the master menu
-Call customer service
-Check your airtime balance
-Buy data bundle
-Request your own number
-Load airtime to your account
-Transfer airtime to another user
-Request airtime from another user
-Airtime advance that enables you to borrow airtime to pay back later
-customize call

With Cell C, we have the following services:
-Access master menu
-Load airtime to your account
-Buy data bundle
-Airtime balance check
-Request airtime from another user
-Request your own number in case you forgot it
-Transfer airtime to another user
-Change tariff plan

And with Telkom, we can perform the following services
-Access the master menu
-Balance inquiry
-Special offers
-Check IMSI
-Request your own number
-Transfer airtime
-Send call me back message

This app also has the option which enables you to add your code to the list so can use later.