We've seen plenty of mockups and rumored parts for Apple's next iPhone that show an elongated form, but a report from 9to5Mac provides the most convincing evidence we've seen so far: 9to5Mac says that it was able to run the iOS Simulator at the next iPhone's rumored resolution of 1136 x 640, and that iOS 6 is "completely scalable to a larger display." The report indicates that this is the only resolution that supports scaling, and that when scaled, iOS 6 adds an extra row of app icons to the home screen: the additional row of apps did not appear at any other resolution besides 1136 x 640. 9to5Mac says that it tested the scaling using a tweaked iOS Simulator application (included in the iOS development tools), and that it tested the resolution in both iOS 5.1 and iOS 6 — and as you can see from the image above, the same resolution in iOS 5.1 merely stretches the four-row set of icons. Obviously this is all still rumor at this point, but with the next iPhone expected to be unveiled in September, we'll see what Apple's really working on soon enough.