Apple has just issued an ultimatum - make your apps iOS7 apps by February or they don't get into the App Store. 

There was a time when the companies responsible for the platforms we write for would persuade and entice us into writing for their latest offering. Now in the era of closely controlled "walled gardens" they can simply tell us what is best for us. The term "walled garden" conjures up a green and pleasant place and perhaps it is if you are making large sums of money from your app but if even part of your programming is about something more than money it should still leave an unpleasant taste. You don't have to be a free software nut to find the way Apple and Microsoft and to a lesser extent Google have erected barriers around their programming disturbing. For most of the time you can forget you are on a lead until it is suddenly yanked. 

This current "yank" makes some sort of sense when viewed as an attempt to cure fragmentation. From February 1st all apps submitted to the App store have to be iOS7 optimized and compiled with Xcode 5. This means that new apps will only work on devices running iOS7. 

Users are informed of upgrades but they don't have to install them. Currently Apple estimates that 76% of devices are running iOS7 with 20% still running iOS6 and the remaining 4% still with older versions.

Of course iOS7 is the biggest UI change since iOS was introduced and apps that use the older "richer" style of UI are going to look different from the rest of the system's flat design. Some developers simply don't like the new UI and would rather stick to their original designs but this is no longer to be allowed. An app has to look like an iOS7 app or you can't sell it.

The idea of moving to iOS7 is a reasonable proposition for any app developer who likes the new flat UI but having it enforced seems unnecessarily heavy handed. It is a bit like pulling on the lead even though the dog is going in the right direction and walking to heel. Imagine the outcry if Microsoft was to rule that developers had to produce Windows 8 apps rather than Windows 7 apps!

There is also the issue of when a developer is free to innovate and introduce new UI elements. Apple might or might not allow them through. All in all it sounds like a recipe for eliminating innovation.  

The move comes ahead of the release of iOS7.1 which is still in beta.