Software for iPhone app development

Absolutely. Check out the AppMobi, which allows for HTML5 and CSS3 driven apps and games to be easily built, compiled, released and sold for Android, iStuff, and Windows Mobile devices.

Titanium. .... and it's free!

Did you mean IDE?

xcode - IDE from Apple.

XCode (Available at the Apple Developer site)
The iPhone SDK (Available at the Apple Developer site).

I'm a big fan of using phonegap & Xcode.

Ok - a couple of varied opinions in this thread, I can tell. Firstly, we work very closely with GearTribe who have a wealth of experience when it comes to mobile app development. They are very big on choosing the right tool for the job. I would honestly stay away from PhoneGap at this juncture, unless you are a particularly proficient developer, as it is horrendously slow with jQuery Mobile UI, and not much better with Sencha Touch. Learning Objective-C also seems like overkill for the most part, as Android is a growing market, and you ignore it at your peril.

Thus your choices become smaller. Mosync have a great system in Wormhole, but it still has a way to go before it gets to the level of support other development platforms have. Rhomobile is also excellent, but our weapon of choice for Android and iOS development is Appcelerator Titanium. It requires only a passable knowledge of HTML, CSS and JavaScript to begin using. Additionally, if you browse the store on Appcelerator's website (https://marketplace.appcelerator.com/) as well as on ChupaMobile (Chupa Mobile - Category Products) you will see that people have entire boilerplate apps for a few Dollars. Buy one of those, customise, modify, and you've got an app that compiles to an Android and an iOS binary.

XCode and PhoneGap

Various development languages and softwares are available on the internet which help you build an iPhone application. Various people have varying opinion about a software. In my opinion HTML 5 is one of the best solution for iPhone app development because it is the latest version of HTML and it includes various features specifically for mobile app development. Hence professional developer uses HTML 5 for mobile app Development.

if you check out the Apple site, you will come across several tools with which you may create wonderful apps both for iPhones and iPads. A couple of such software are XCode and iPhone SDK. However, Titanium is also a good one. My suggestion would be to try a few software and then decide which is easy and useful as per your judgement. I would love to get some feedback about my recommendations.

Here, Vinfoys doing Iphone/Adroind app development services,

hit me on skype: vkappletech

I'd recommend you to use xcode.

I am using PhoneGap for the iphone apps development and i am quite satisfied with it so would advice you to use same for your apps development

you need to enroll to the Apple Developer's program and get XCODE

You can use "Titanium"

I have found from having an app rejected from the Apple platform, that you really need to pay attention to making sure your app is mostly native and less web based. With Android, it does not matter so much. So HTML 5 is good but you might also want to combine a little of PhoneGaps features as well.

There are lots of tools available for developing an iPhone app. These tools are help you to build your own app successfully. Without programming and script, any one who can develop the apps successfully using the following tools.
Few of the good tools to proceed with are
1.Swep Apps
2. Appincubator
3.Kanchoo
4.AppBreeder
5.MyAppBuilder
6.BuildanApp
7.eBookApp

As a mobile app developers Atlanta, these above tools are so useful for my knowledge growth and build my apps successfully.