On Tuesday, Apple told developers of iOS apps that any new or updated apps must be iOS 7 compliant after February 1. After the deadline, only apps built with the latest version of Xcode 5 will be reviewed for approval by the Cupertino company.

Since the arrival of the iPhone 5S, Xcode 5 has been able to handle 64-bit processes, and it lets developers create new interfaces more in tune with iOS 7's new design direction. It also gives developers access to new APIs, like the ones that govern backgrounding. Developers using Xcode 5 can still target older versions of iOS, but it's clear that Apple wants its developers to start targeting iOS 7 sooner rather than later.

The post on Apple's developer's site also refers curious readers to its “iOS Human Interface Guidelines” page for more information about iOS 7's general aesthetic. As iOS 7 is one of Apple's more visually divergent version updates, it's no surprise that getting apps to conform to that new look is one of the company's latest concerns.

TechCrunch points out that Apple is strong-willed about getting its users to adopt new iOS versions, to the point where it claims on its developer's website that 76 percent of all iOS users were on version 7 as of December 15. The new requirement addresses that big chunk of users that will only grow in the next two months or so.