So, here's our list for iOS. We'll be building an Android version shortly, and quite likely a General MobAppSec version as well.
iOS"iOS Security", May 2012, Apple, Inc. -- Say whatever you want about Apple's security practices. This guide provides a superb description of iOS's security architecture, from its boot process through all of the app-level protections provided by current iOS versions. This is a must read for anyone involved in iOS application development.
"Hacking and Security iOS Applications - Stealing Data, Hacking Software, and How to Prevent It", January 2012, Jonathan Zdziarski. -- Although it is largely focused on forensic analysis of iOS devices, this book is another absolute must read for iOS developers. In it, you'll learn how jailbreaking works, how to copy the contents of an iOS device's hard drive, how iOS encryption works in detail, among many other things. It includes several labs for the reader to work through, along with available source code for each.
"Security Configuration Recommendations for Apple iOS 5 Devices", March 2012, U.S. National Security Agency. -- Although more aimed at IT Security than MobAppSec audiences, this document provides some useful tips on how to configure iOS 5 devices and how to manage them in large enterprise environments.
"iOS Hardening Configuration Guide - For iPod Touch, iPad, and iPhone running iOS 5.1 or higher", March 2012, Australian Department of Defence. -- Conceptually similar to the NSA guide above (but written in Australian English :-), this useful document provides useful security configuration tips for iOS deployments. It also goes into good detail on how the platform's security features work, and is worthwhile reading for everyone involved in iOS application development.
"iOS Developer Cheat Sheet", July 2012, OWASP. -- This doc provides some quick pointers on how to avoid many of the major risks associated with mobile computing. The doc follows the (draft) OWASP Top Ten Mobile Risks, and points to possible solutions to consider for each. It is an open source document from OWASP, and others are encouraged to contribute and participate in expanding and improving it over time. (Full disclosure: I (@KRvW) was the principal author of the first version of this doc, so I'm somewhat biased...)