If you're developing production apps you're likely supporting at least the last two versions of iOS. I'm a full-time iOS developer and don't remember half the n

If you're developing production apps you're likely supporting at least the last two versions of iOS. I'm a full-time iOS developer and don't remember half the new stuff in iOS 9 simply because I don't need it yet or it's iOS 9 only and I have to support iOS 7+. Also all of that knowledge transfers. iOS 10 will bring extra deeper stuff that you're not going to get anywhere near learning on an intro course.