Thank you for contacting us and for the opportunity to help!
I'm not positive if the 5th edition covers iOS 9.3, but I will inquire with the editor. Given that it was released in June 2016, I would imagine that it would cover the latest iOS version. The 6th edition is set to release in November, and that correlates with the expected release of iOS 10. Once I hear back from the editor, I will post an update.
Please let me know if you have any questions. Have a great day!
thanks, just bought the book.