As an application developer, you can find Apple's iPhone to be the ideal platform to develop and sell killer apps and make good money. However, its not so easy as it sounds. There are few restrictions laid down by Apple, which as a developer, you should think before going to develop an iPhone application.

Apple says "Only one application can run at a time." So, this means if you are running an application and some one calls you, then you have to quit the application to answer the call. Suppose a user is on a secure server and have to frequently leave the page, then it becomes a headache for the user to give username and password every time.

A point for the developers to think about. Suppose you have developed a GPS application which needs constant support from the user to collect a particular data for your geo-location, then again it makes a compulsion for the user to continue with the same application and ignore all important calls for the application. This makes the impact of that application vague.

Apple says "no third party application will run in background". This means while you are taking an important call instant messengers will not be able to collect messages for you. You will be shown offline as soon as you switch to take your call.

Apple has its official App Store. No one can directly distribute any apps outside this App Store. It not only acts as a marketing point for the developers but can prove a gateway for the iPhone application developers. As an iPhone developer, you need to get registered yourself with Apple. When you submit your developed app to Apple, after review of the app they will decide whether the app should stay in the App Store or not. There are again threats for you that they may reject your apps or make significant delay in the release.

So these are the few of the restrictions or advantages you can get as an iPhone application developer.So, get started with iPhone development and try to change the limitations so that we get a better iPhones with more killer apps.