An uber list of every iOS Engineer resource, app, and tool I can find.
The usual suspects from Apple.
A simple guide for setting up Certificates, ID's and Provisioning profiles that work well for teams.
https://github.com/simpleweb/iOS-Development-For-TeamsFacebook's iOS Infrastructure - Mobile @ Scale
https://code.facebook.com/videos/232867676889263/facebook-s-ios-infrastructure-mobile-scale/world-class command line utilities for iOS development
http://nomad-cli.com/A Ruby gem for inspecting iOS IPAs
https://github.com/soffes/lagunitasCalabash is an automated testing technology for Android and iOS native and hybrid applications.
https://github.com/calabash/calabash-iosFast Project navigation for Xcode
http://codepilot.cc/CocoaPods is the dependency manager for Objective-C projects.
http://cocoapods.org/Chisel is a collection of LLDB commands to assist debugging iOS apps.
https://github.com/facebook/chiselAll about iOS delivered right to your inbox.
Names of iOS Engineers, and Twitter lists of great resources for iOS Engineering.
Blogs to read.
Websites that offer instructional videos about iOS Engineering.