Commonwealth Bank has added a foreign exchange "toolkit" to its mobile banking platform, allowing users to check forex rates in 33 currencies and set currency alerts.Boasting 100,000 mobile users signing on each day, the bank has mobile apps for the iPhone, Android phones and Windows Phone 7. It also has tablet apps for both the iPad and Android tablets.The bank says it is working on a payment application for Facebook and will deploy near-field communications for payments as soon as the technology is ready.But at the moment the big selling point of the CBA's mobile banking service is the real-time account updates enabled by the bank's core system upgrade.Most mobile users sign on to check their account balances and check recent transaction histories. CBA is the only local bank that can boast real-time transaction reporting.