Last week the Wall Street Journal, Reuters, and Bloomberg all reported that the next iPhone will have a 4-inch screen. Of course, no one knows for sure, but lots of evidence is pointing that way. The main questions have been whether it would create problems for developers and also whether it would fragment the market. iMore had a lucid article about Apple's options for a larger screen and what it would mean. If, for example, a larger screen changes the aspect ratio, it means that apps would generally have to be rewritten — and that it would take a lot of work.