9to5 Mac says that it has heard word from an app developer that it has noticed that the “iOS6” string has all of a sudden popped up in its analytics software, which of course means that someone, somewhere, is running the developer’s app on iOS 6. The developer is unable to pinpoint exactly when this started happening, but has narrowed it down to within the past week. 9to5 Mac says that it has also heard from other developers who saw iOS 6 strings appearing in their analytics software from late April onwards. 9to5 Mac says that this could well mean that Apple has started iOS 6 compatibility testing with apps from the App Store, as this was exactly what happened last year prior to the launch of the next iOS. 9to5 Mac has previously reported that it believes there to be many different versions of iOS 6 “floating around” Apple’s headquarters, possibly readying for a rumoured launch at Apple’s World Wide Developers Conference in June.
Source: Developers begin seeing iOS 6 hits in App Store application usage logs | 9to5Mac | Apple Intelligence