Commonwealth Bank's chief executive, Ian Narev, confirmed that the bank had experienced unforeseen challenges with the development of its mobile point-of-sale platform being developed in Europe in association with Wincor-Nixdorf.The device, dubbed Albert, was announced with great fanfare in July 2012, but has yet to materialise. A second mobile point-of-sale device, Leo - essentially, a case which turns an iPhone into a payment terminal - was announced at the same time and is available, but only for the now dated iPhone 4 and 4S models.  Speaking at the bank's interim results presentation yesterday, Narev acknowledged the delay. "Nothing has gone long-term wrong, but it's taken a bit longer than expected," he said.Narev said the leading-edge nature of the technology had made the manufacture of Albert terminals a little more complex than expected.In particular, he said, the type of glass needed for the tablet device was "very complicated", although other manufacturers of Android tablets have successfully sourced this glass.Wincor-Nixdorf, however, CBA's partner in the development, had, by its own admission, no experience in the field before partnering with Commonwealth Bank.Narev said that the device was still in development "and will be rolled out very shortly", although he did not specify a date.Despite this hiccup, mobile technology continues to be an investment focus for the bank, and Narev claimed that more than one million downloads of the Commbank application (which supersedes its first mobile payments app, Kaching) had taken place since it was launched in December.