The latest iteration of Apple's mobile operating system, iOS 7, features flatter designs, new push notifications that send notes to users' lock screens, and a more seamless integration with mobile apps, among other features. App developers everywhere -- including those working in the real estate space on popular apps from Zillow, ZipRealty, Trulia, realtor.com and Redfin -- are ramping up now to take advantage of the operating system's new features and make sure their apps are optimized for iOS 7 when it becomes available to consumers sometime this fall. Jeremy Wacksman, vice president of consumer and mobile marketing at Zillow, pointed out that on first look, the enhanced notifications feature of the new operating system is particularly attractive to Zillow. A new listing that's p...