NSScreencast Ben Scheirman at NSScreencast has come up with an interesting way to learn iOS development. He publishes a weekly series of videos to give you insights into iPhone and iPad application development using XCode and Objective-C.
Treehouse With the mission to bring affordable technology education to people everywhere, Treehouse offers a number of iOS development resources which help you learn about everything, from C# basics and iOS tools to unit testing and building a blog reader.
Geeky Lemon Xcode Tutorials The XCode 6 tutorials by Geeky Lemon are brilliant for learning how to create awesome iPad and iPhone apps. With step by step video walkthroughs and easy to copy/paste code, these tutorials have made learning iOS development a tad simpler
Avocarrot iOS Cheatsheet Avocarrot maintains this cheat sheet on GitHub for iOS developers, which includes basics of Objective-C, commonly used frameworks and C related code.
NSHipster This journal tries to cover those aspects of Swift, Objective-C and Cocoa which are often overlooked. You can find a huge compilation of articles and tutorials on the site that can help you deal with iPhone/iPad development like a pro.
Ray Wenderlich Blog Focussed on helping novices learn iOS development quickly, the Ray Wenderlich blog features over 750 high quality tutorials. They explain the most challenging topics in a way that’s easy to understand for everyone.
Code School The Code School offers 4 main courses in iOS development – Objective – C, iOS Fundamentals, iOS and XCode Challenges. These courses cover all the key aspects of iPhone and iPad development, thus helping you bring your app ideas to life.