Ever since Apple's purchase of biometric sensor company AuthenTec last year the rumor mill has been abuzz with predictions that a future iteration of the iPhone would employ built-in fingerprint authorization. Now, as 9to5Mac reports, Twitter user Hamza Sood has discovered a folder in the newly released iOS 7 beta 4 that references a biometric user interface, complete with descriptions of a setup process that includes images of a color-changing fingerprint a
