Unsurprisingly enough, some developers have reported begun seeing references to iOS 7 and iPhone 6 in their usage logs, according to The Next Web:

One developer showed us that Apple has been testing hardware relating to a new ‘iPhone6,1? identifier, powered by a device running iOS 7, which is expected to be released by Apple in the middle part of this year.

The current iPhone 5 shows the identifiers ‘iPhone5,1’ and ‘iPhone 5,2’ based on different 4G/LTE configurations. The usage logs seen by TNW note they originate from Apple’s Cupertino headquarters, hinting the company is testing applications on unreleased software and hardware. These usage logs can be easily faked, but we can always assume Apple is testing new hardware and software, so these logs will always come up year after year, especially with WWDC 2013 expected to take place this summer.