今日、Appleから届いたメールによると、いままでプラットホーム毎に分かれていたデベロッパープログラムが単一のプログラムに統合されるとのことです。OS Xのプログラムにしか入っていなかったけど、いつのまにかiOSもOKになった模様 
We are excited to announce the new Apple Developer Program, which combines everything you need to develop, distribute, and manage your apps on all Apple platforms into one single program. Your developer program membership has been automatically updated to the new Apple Developer Program.
This new program provides:
Distribution of your apps to over a billion Apple customers around the world on the App Store for iPhone, iPad, Mac, and Apple Watch.
More continuity capabilities for iOS and OS X, including app extensions
and Handoff.
The latest beta releases of iOS, OS X, and watchOS announced today, so you can get started on your next app.