Commonwealth Bank has finally released an Android version of its Kaching mobile payments app. It has also upgraded the version of the app for the iPhone - the app that allows payments to be made between two Kaching-enabled iPhones by physically bumping them together.Kaching for Android will work on 13 different devices, but a near field communications (NFC) facility - which allows contactless payments - is not available for Android at this stage. While the bank supplies an NFC-enabled phone case for iPhones, it was not prepared to sell 13 different NFC cases for Android users.Android users will instead have to wait for NFC-enabled phones. That group of customers will also have to wait for the US software house that developed the "bump" capability for iPhones to offer that capability for Android.The bank yesterday said that of the more than 365,000 notional users of the iPhone version of Kaching,  150,000 people used it each day. The bank handles A$1 billion worth of payments through Kaching each day.Andy Lark, CBA chief marketing officer, said that mobile banking was now growing exponentially, with more than $5 billion being transacted each year through mobile devices such as smartphones. He said 46 per cent of the interactions with Netbank come via a mobile device, with the bank anticipating that a "tipping point" would occur very soon.Credit Union Australia, meanwhile, yesterday launched mobile banking apps for iPhone and Android. CUA said in a statement that the service was the "first major deliverable in CUA's partnership with Tata Consultancy Services", which is building the mutual's new core banking system.