Mobile web advertising and optimizing company Onswipe is reporting that interest in the iOS 7 beta is growing at a furious pace, with three quarters of a percent of the iPhone user base already running the software in beta. The figures represents at a minimum more than two million iPhones, far higher than those running the iOS 6 beta at the same point in its development cycle. While some of that figure may be users who have pirated the (notoriously unstable and buggy) beta, most is believed to be developers who need to match their apps to iOS 7’s new look….