Nearly three months after the launch of iOS 7, three-quarters of all mobile devices from Apple are running the newest operating system, Apple and others have agreed.Apple started serving iOS 7 on Sept. 18, and shipped the operating system on its fall wave of new products, including the iPhone 5S and iPhone 5C -- which went on sale later that month -- and the iPad Air and Retina-equipped iPad Mini that reached retail last month.Almost three out of four devices that accessed the App Store for the week ending Dec. 1 ran iOS 7, Apple said on its developer website. (Image: Apple.)According to Apple's iOS developer support site, 74% o the devices tapping the App Store for seven days prior to Dec. 1 ran iOS 7, more than three times the next-most-popular edition, last year's iOS 6.Apple's number closely matched those of third-par