Rumors are swirling this week that Apple may be planning on releasing a new iPhone with a different screen. This is the normal fantastical speculation about future tech products that effect most popular products. The same kind of speculation comes up around the time of new game consoles. The media tends to spend a bit more time with the Apple rumors but that is neither here nor there. The great thing about speculation has less to do with its factual basis, of which there is usually very little, but what it say about consumer desires and expectations. The anatomy of the current rumors has deep implications for the iOS platform.
The current rumors hint at Apple producing a larger screen. At first glance this seems like a no brainer, but there are several technical aspects that need to be solved before you just bump up screen size. The current iPhone has a 3.5 inch screen with a resolution of 640x960 with a pixel density of 326 pixels per inch (ppi). These three variables determine a lot about the overall product.
When Apple released the iPhone 4 they made a big deal about the ppi they defined this as creating a retina like screen, a screen perfect for your eye so you cannot discern individual pixels. This shapes expectations; it says Apple cannot release a product with a lower ppi without damaging the branding. When the iPad 3 was released (I'm not calling it the new iPad) they immediately faced criticism when they said it had a retina display. People pointed out that the ppi was only 264 and therefore wasn't as "good". Defenders pointed out that the optimal distance of the iPad was much greater than that of the iPhone, and when you've account for that difference in holding they were equivalent. While the whole retina marketing may or may not be true one thing is true, people can tell the difference when you decrease the ppi. The difference between my phone the HTC sensation (@256ppi) and the Galaxy S2 (@219ppi) is painfully obvious.
This puts Apple in a very difficult position. When the first iPhone came out it was one of the largest screens available on a mobile device. Now compared to the rest of the market they are on the low end spec wise in terms of screen size. There is no question that the iPhone has a lot of quality in that small package, but at this point when every flagship phone from Nokia, to Samsung, to rim (pending) will have a screen size of 4 inches or greater; the sheen on the iPhone screen size is beginning to lose its luster. In order for Apple to release a new iPhone, maintain ppi, and increase screen size, they will have to fiddle with the aspect ratio. The problem is doing this introduces something relatively unthinkable in the Apple world, fragmentation.
Currently there are only 4 possible screen configurations for iOS, one for current gen iPhones/iPod touches, one for the current gen iPad, and a legacy configuration for each. The difference between current gen and legacy in both cases is a factor of two, meaning the iPhone 4 has twice the pixels of the 3GS. This makes software development relatively easy, layout only has to be done twice once for the iPhone, and once for the iPad, and to support legacy devices images need only be reformatted to a lower resolution. No changes need to be made to overall design. Changing the resolution breaks all of that. Developers would have to design a layout for a new iPhone, the current iPhone, and the iPad. This might not seem like much of a difference but developers say layout design can eat up to 50% of the design process.
Still there is a big reason why people suspect iPhone will increase the screen size: LTE. Both AT&T and Verizon are pushing LTE as the must have feature on any smart phone. Unfortunately the LTE chip has two problems: LTE chips are physically big right now and they have a dramatic effect on the battery life of your phone. As a result phones with LTE chips need larger batteries and more space. In order to achieve this without increasing the overall thickness of the device, manufacturers are building phones with bigger screens. You can see this with the iPad 3 in order to achieve the same battery performance of the iPad 2 they had to significantly increase the size of the battery which made the iPad 3 the only Apple product I can think of that became thicker. Apple really can't go back The 4s already received significant criticism for not including LTE.
The question is if they do change the resolution of the new iPhone what will it do to the platform. While this change may seem minor it fundamentally changes the way developers will have to think about design for the iPhone. Right now iPhone/iPod apps and iPad apps are treated as different apps. Developers could choose to treat the new iPhone as just another app and develop three different versions of the same app, but that could be potentially time consuming and costly. The alternative would be to embrace something that until the iPhone came out was standard relative layout design.
Outside of the mobile space relative layout design is a given. With computers there is no way of knowing as a designer if a user is going to have a 11 inch laptop display or a 27 inch desktop monitor, or if they will operate it full screen or in a window. As a result elements are designed to grow and shrink relative to the screen. Designing this way maybe more labor intensive at first but is a much more versatile and future proof. The mobile space is still evolving and growing and to limit it to a specific feature set limits the possible experience and could stifle innovation.
Apple is now at the crossroads. I don't believe Apple will go in the Samsung direction of offering a device at every screen size imaginable. Having limited choice made it easier for developers to build up the platform to what it is today. At the same time it is now showing signs holding Apple back. This is something wholly out of Apple's DNA. Legacy support is not what Apple is known for, the original iMac made waves for banishing the antiquated floppy drive; The MacBook air has done the same with cd drive. Apple wants to remain at the forefront of innovation, but it is hard to see how it will do this without changing the way the OS works in the long run. If Apple does fragment the OS, the only thing that is certain is the spin at the next Apple event will be magical.