Hugh Pickens DOT Com writes "Chuong Nguyen reports that Apple is forcing developers to adopt iOS 7's visual UI for their apps, and has advised iOS developers that all apps submitted after February 1, 2014 must be optimized for iOS 7 and built using Xcode 5 ... 'It's likely that Apple is more anxious than ever for developers to update their apps to fit in visually and mechanically with iOS 7, as it's the largest change in the history of Apple's mobile software,' says Matthew Panzarino. 'iOS 7 introduced a much more complex physical language while stripping out many of the visual cues that developers had relied on to instruct users. For better or worse, this has created a new aesthetic that many un-updated apps did not reflect.' Most app developers have been building apps optimized towards iOS 7 since Apple's World Wide Developer Conference in June 2013. Apple has been on a push over the past couple of years to encourage developers to support the latest editions of its OS faster than ever. To do this, it's made a habit of pointing out the adoption rates of new versions of iOS, which are extremely high. Nearly every event mentions iOS 7 adoption, which now tops 76% of all iOS users, and Apple publishes current statistics. In order to optimize apps for the new operating system, they must be built with the latest version of Xcode 5 which includes 64-bit support and access to new features like backgrounding APIs."