Free iPad, iPhone, iOS Programming Resources

iOS 7 App Development Essentials
This is another techtopia book by the same author as the previous version.

iOS (iPhone, iPad) Tutorial
Covers getting started and setting up the environment, the basics of Objective-C, a first iPhone app, audio, video, the SQLite database and other topics.

Start Developing iOS Apps Today
This is the Apple Developer Library official guide to creating apps using their tools. Sections have links to further resources such as info on frameworks and so on.

Objective-C 2.0 Essentials
The Objective-C 2.0 Essentials online book contains 34 chapters of detailed information intended to provide everything necessary to gain proficiency as an Objective-C programmer for both Mac OS X and iPhone development.

iPhone iOS 6 Development Essentials
Free iPhone programming book online.

Writing iPad apps: what you need to know.
Paul Ockenden offers practical advice on building apps for Apple's tablet.

How to Develop iPad Apps
How to Get Started Developing iPhone and iPad Apps

iOS App Programming Guide
This is the Apple iOS developer site. It describes the fundamental architecture of iOS apps and guides you to the other documents in the iOS developer library that contain more detailed information about how to address a specific task.

Maqetta is an open source project that provides WYSIWYG visual authoring of HTML5 user interfaces. The Maqetta application itself is authored in HTML, and therefore runs in the browser without requiring additional plugins or downloads. You can run it remotely or download it and run it locally. Allows creation of interfaces for mobile devices. (You need to register with a valid email.)ads.

How to Make an HTML5 iPhone App
This is a tutorial specifically for iPhones but most of these techniques apply to all phones that have HTML5-capable browsers.

An Objective-C class to compress or uncompress zip files, According to the author it can be used for iPhone application development, and cocoa on Mac OSX as well.