But with currently more than 100,000 apps officially available from the App Store, it's kind of hard for a developer to ignore the potential market the iPhone provides.
And there are apps for virtually anything you could think of, from games to productivity apps to horoscopes to news and more.
Below are 70 tools, tutorials, and resources to help you get started developing your own iPhone apps. There's everything from basic tutorials to templates to resource libraries to help you on your way.
How to Get Started with iPhone Dev
A very thorough article on how to start developing your own iPhone apps.
Learn How to Develop for the iPhone
An excellent tutorial from Tuts+ that covers the development of websites specifically for the iPhone or iPod Touch.
First iPhone Application
This post from iPhone SDK offers an extensive overview of how to develop your first basic iPhone application.
How I Wrote an iPhone Application
This article gives a first-hand account of building an iPhone app, including the thought process behind development and some code snippets.
Cocoa Touch Tutorial: iPhone Application Example
This tutorial covers how to develop Cocoa iPhone apps using Interface Builder to quickly build your first application.
Sliding UITextFields Around to Avoid the Keyboard
This tutorial covers the basics of moving text fields around on an iPhone app so that they don't interfere with the on-screen keyboard.
Develop iPhone Web Applications with Eclipse
A very comprehensive article from IBM on using Eclipse to develop your iPhone apps.
iPhone Development with PHP and XML
Another article from IBM on developing apps, this time with PHP and XML.
Developing iPhone Applications Using Ruby on Rails and Eclipse
The first in a series of articles from IBM on using Ruby on Rails and Eclipse to develop iPhone apps.
Your First iPhone Application
A tutorial for creating your first app, from the official Apple iPhone OS Reference Library.
How to Make an iPhone Application on XCode
A simple video tutorial that shows you how to build an iPhone app on XCode.
iPhone SDK Development Tutorial - First Step Towards the App Store
Another great video tutorial that shows the first steps in building apps for the app store using XCode.
Make an iPhone App Using the Envato API
A great tutorial from Tuts+ that shows you how to use the Envato Marketplace API to develop your own iPhone apps.
Building PhotoKast: Creating an iPhone App in One Month
This photo tutorial shows you the complete process of building an iPhone app, with illustrations.
Perfect Multi-Column CSS Liquid Layouts: iPhone Compatible
This tutorial shows you how to build liquid CSS layouts that are iPhone compatible.
iPhone Dev Sessions: How to Make an Orientation-Aware Clock
This tutorial covers how to build an orientation-aware clock, which provides great insight into building any app that is orientation-aware.
iPhone SDK: Interface Builder Tutorial
A very short, simple intro to how the Interface Builder works.
Parsing XML Files
This tutorial from iPhone SDK offers all the information you need for parsing XML files within applications on the iPhone.
iPhone Gaming Framework: Stage 1 Tutorial
This tutorial shows you how to get your basic screen management system running so you can start developing iPhone games.
iPhone Game Programming Tutorial: Part 1
Here's a complete tutorial for creating a Pong-like iPhone game.
So You're Going to Write an iPhone App...
This tutorial gives a great overview of the app development process and some things to consider while developing.
Advanced iPhone Development
This article looks at some more advanced aspects of iPhone application development.
Building an iPhone App in a Day
A brief look at what it takes to build an iPhone app really quickly.
Build an iPhone Webapp in Minutes with Ruby, Sinatra and iUI
An overview of fast development techniques for iPhone webapps.
Finding iPhone Memory Leaks: A "Leaks" Tool Tutorial
Learn how to find memory leaks in your iPhone apps using the "Leaks" tool.
iPhone Application Development, Step by Step
A great, step-by-step look at the app development process.
iPhone App Development: Where to Start
A great article that talks about iPhone app development from the perspective of someone who's never done any Apple or Mac development (or even used a Mac) previously.
Parsing XML on the iPhone
Another great look at how to parse XML within iPhone apps.
iPhone Development Central
This site offers a huge variety of video tutorials for iPhone developers, broken down for beginner, intermediate and advanced developers.
iPhone SDK Tutorial: Reading Data from a SQLite Database
A simple tutorial for using SQLite with the iPhone SDK.
iPhone Dev Sessions: Create a Navigation-Based Application
This comprehensive tutorial shows you how to create a navigation-based application from XCode.
iPhone SDK Tutorial: Build a Simple RSS Reader for the iPhone
This tutorial shows you how to build a simple RSS feed reader from the ground up.
Multi Touch Tutorial
This tutorial gives a great introduction to the iPhone's multi touch interface.
Howto: iPhone Application Development Environment
This tutorial shows how one developer set up their app development environment, with tips for setting up your own.
iPhone Application Programming
Downloadable lectures from Stanford's iPhone Application Programming class.
Introduction to iPhone Application Development
Downloadable course materials from a one-week MIT course on iPhone app development.
iPhone Programming Tutorial - Using openURL to Send Email from Your App
This tutorial shows you how to use openURL to allow your apps to send email.
How to Create Your first iPhone Appllication
Another comprehensive tutorial for creating your first iPhone app from the ground up.
Morfik is a downloadable tool that speeds up development of rich internet apps.
iPhone GUI PSD 3.0
A set of downloadable Photoshop files with iPhone GUI images.
iPhone PSD Vector Kit
A PSD set that comes with several button elements as well as six different iPhone interface options.
iPhone Wire Frames
iPhone Wire Frame stencil files for use with OmniGraffle.
Yahoo! Design Stencil Kit
A downloadable package of UI stencils from Yahoo! that includes iPhone images.
iPhone UI Vector Elements
Downloadable vector images of different iPhone elements.
A library of open source iPhone app elements and frameworks.
The Google Data API's Objective-C client library.
Are You iPhoned?
A simple site that checks to see if you're visiting from an iPhone and gives you the code to do the same on your own sites.
31 iPhone Applications with Source Code
A library of more than thirty iPhone apps with their source code available.
Sample UI elements for the iPhone.
iUI: iPhone User Interface Framework
A free UI framework for Safari development on the iPhone.
35 Free Icon Sets for your iPhone
35 icon sets you can download and use in your iPhone development.
TestiPhone.com - iPhone Simulator
An iPhone simulator for testing your iPhone web apps.
Another simulator for testing your iPhone web apps.
Resources and Articles
iPhone Dev Connection
Apple's official iPhone development site.
The Darker Side of iPhone App Development
An article that covers some of the restrictions and limitations imposed by Apple for iPhone apps.
Avoiding iPhone App Rejection From Apple
A great article that tells you how to not get rejected by the App Store.
14 Essential XCode Tips, Tricks and Resources for iPhone Devs
A roundup of some great developer resources.
An iPhone/iPod touch development discussion forum aimed to assist fellow developers as they code in Apple's SDK. There is also a job board where developers and entrepreneurs can share and discover one another's services to start projects of their own.
The iCodeBlog has tons of great articles, news, and tutorials related to iPhone development.
An iPhone developer resource center and community.
A blog that covers news, apps, and more related to the iPhone.
iPhone Open Application Development
O'Reilly Media's iPhone application development book.
iPhone Web Application Submission
The official place to submit your iPhone web applications.
iPhone Application and Website Development: All Tools and Tutorials You Need
A huge roundup of resources for developing both iPhone apps and optimized websites.
iPhone Dev SDK Forum
A great forum for getting answers to your iPhone SDK development questions.
iPhone Application Developer Interview
An interview with iPhone app developer Darren Andes, the developer of the Baby Tracker: Nursing app.
Seven Things all iPhone Apps Need
An overview of some must-have features for iPhone apps.
5 Free Resources for iPhone App Development
A roundup of some handy, free resources for developing your iPhone apps.
Top 10 Tutorials to Develop iPhone Apps
A ranked listing of great iPhone development tutorials.
100 Free Courses and Tutorials for Aspiring iPhone App Developers
A huge list of iPhone development courses, many from traditional universities.
29 iPhone App & Website Development Resources and Tutorials Places
Another excellent roundup of iPhone development resources.
Compiled exclusively for WDD by Cameron Chapman.
Did we miss your favorite resource? Please add it in the comments below...