Shelly Brisbin has updated her excellent iOS Access for All for 2019:
This is the sixth edition of my book, and it’s fully updated for iOS 12.1. The book has grown along with Apple’s mobile software – its 168,000 words, with a page count that varies by platform, but that’s between 700 and 800 pages on many platforms. But more important than word or page count, iOS Access for All remains most comprehensive iOS accessibility resource anywhere!
This is the book when it comes to the topic of accessibility and Apple platforms.