'Programming In Objective-C' by Stephen Kochan is a definitive guide to mastering Objective-C, the core language for iOS and OS X app development. Ideal for beginners and experts alike, this book offers clear explanations, practical examples, and exercises to enhance learning and application skills.

'Xcode 3 Unleashed' by Fritz Anderson is an essential guide for developers seeking to master Apple's Xcode 3. Covering everything from basic setup to advanced features, this book offers practical examples and expert tips to enhance your development workflow and create standout applications for macOS and iOS.