If you did not know already, Apache Flex is a technology (a software development kit or SDK) used to build, and deploy cross-platform mobile applications or rich Internet applications (RIA). The technology has been donated to Apache in 2011, but still uses Adobe AIR or Flash Player as runtime. For many years, Adobe has been doing a great job of keeping its runtimes compatible with Apple's guidelines and requirements.
A recent problem
In the past weeks, Apple announced that "Starting February 1, new apps and app updates submitted to the App Store must be built with Xcode 5 and iOS 7 SDK." Could this really mean the death of Flex applications for iOS?
Fortunately, Adobe released a fix that is currently available through the latest beta release of Adobe AIR. So if you plan to publish on the App Store soon, you should re-run the Apache Flex SDK Installer, and where the installer asks you to select an AIR version, just select AIR 4.0beta. Proceed with the installation, and that's it! Now build your app as you have always done, and enjoy the power cross-platform development!
Update (March 2nd, 2014)
Please note that Adobe just changed the AIR versioning from 4.0 to 13.0 to synchronize it with Flash Player. When running the Apache Flex SDK installer, select the latest AIR version: AIR 13.0beta.