It looks likely that the iphone 5 is to get a 4 inch screen, but there’s a catch. The catch is that only the height of the screen is being increased according to iLounge, they go on to say that the height of the screen is being increased by 11mm or 0.45 inches.  This will allow for an extra row of icons being added to the screen. This will also make the iphone about 10 mms taller than the previous iphone 4s, so consequently increasing the bulk of the phone so possibly upsetting potential customers. Also if they did up the screens height it would prove to be a headache for app developers moving from a 4:3 aspect ratio to a 16:9 aspect ratio. The best thing Apple could do is increase the phone screen size diagonally up to 3.7 or 4 inches. This would keep everything proportionate so making it easier for apps developers to accommodate their apps. Adopting  a 3.7 inch screen would also avoid having to increase the dimensions of the phone, so not risking the phone becoming too bulky in size.