An iOS 8 preference list file has been found with an iPhone resolution of 736×414, reports 9to5Mac, which would translate to a Retina “2X” screen resolution of 1472×828. At a 4.7” screen size, this would be around 359 pixels per inch (PPI), versus a 307 PPI resolution for 5.5” — the latter just enough pixel density to qualify as a Retina display. If displayed on a 4” screen, this would equal 422 PPI.

Previously, 9to5Mac reported in May that Apple was testing a 1704×960 resolution for the next-generation iPhone, which we noted at the time oddly fell just shy of the “full HD” 1920×1080 resolution found in virtually all HDTVs and many competing smartphones. It’s possible that either or both reports are wrong, however, the 736×414 resolution comes directly from Apple’s latest Xcode 6 SDK betas for iOS 8.
If the new numbers are accurate, it suggests that Apple — rather than merely tripling every pixel from 320×568 as was previously suggested, increasing the level of detail while keeping the same balance of on-screen elements — may instead be adding 94 pixels of width and 168 pixels of height to the existing iPhone UI.
Conceivably, that resolution could enable one additional column and one or two additional rows of Home Screen icons, adding 11-16 more icons to the Home Screen for a total of 35-40. It might also mean additional coding work for game developers, as on-screen art would need to be manually adjusted to fill the extra pixels. 9to5Mac reports, though, that the preference list file suggests the resolution will display the same number of icons—20—as on the iPhone 5, 5c, and 5s.