Apple is said to be testing the iPhone 6 with a 1706 x 960 resolution display expected to measure either 4.7in or 5.5ins.
According to 9to5mac, the next-generation iPhone will have a resolution three times that of its base rate of 568 x 320 pixels. Depending on whether Apple decides to use a 5.5in or 4.7in panel, the ppis of the display would measure between 416ppi and 356ppi.
This increased resolution means developers would need to adjust their apps to display correctly on the screen and Apple is thought to be redesigning its iOS user interface to accommodate these changes.
9to5 Mac's sources say that the core features of the iOS interface will appear like larger versions of those functions on the current iPhone display, but it's likely some preinstalled applications will be redesigned to fit on the larger, higher resolution screen.
Developer Steven Troughton-Smith modified the iOS simulator to show how the increased resolution would affect the existing design of iOS. Although the modifications showed the base elements scale well, some apps like the calendar would need extra elements to fill the screen.
Schematics leaked by Foxconn show the screen will keep the same 16:9 aspect ratio of the iPhone 5, iPhone 5s, and iPhone 5c, but because of the increased physical size of the screen, it will be both taller and wider.
This would perhaps make it easier for developers to scale their apps, which was not the case when Apple introduced the taller iPhone 5 in 2012 and also when Apple launched the iPad and encouraged developers to re-develop their apps to fit both screens.
Previous rumours have suggested that said Apple would be using a 5-inch sapphire crystal display for the iPhone 6, thanks to a deal with GT Technologies. This would change the potential ppi of the iPhone 6 to 391.
The iPhone 6 is rumoured to launch towards the end of 2014, possibly as early as August, after iOS8 is announced at WWDC in June.
