iPhone application development  may be technically easy just because of your adeptness at programming languages and other technical skills. You may be planning to develop the best of the iPhone application and put it up for sale to the iPhone users. Before doing this you should be aware of the restrictions that Apple Inc. the designers of iPhone, have applied. These restrictions could have an adverse impact on your creativity and application development plan. Some of the prominent restrictions that could limit your scope of developing the applications are as follows.

Either or:
One of the major restrictions applied by Apple is that the user can run only a single application at one given time. This implies that two applications cannot be run simultaneously, no matter how important both are.
Suppose, you receive a call while you are using the internet, either you stay glued to the internet and not attend the phone or exit from the internet to attend the phone. You cannot do the two things simultaneously. This is one great issue for the application developer because it may reduce the relevance of the applicaion.

Suppose you are in the midst of an application pertaining to the trading of stocks in the market. This required inputs from you in the real time. Now when you are going to implement a crucial decision of buying or selling the shares, you start getting an equally important call. Now either you can attend to the call or you have to continuing the trading. You can run only a single application at any given point of time but not both simultaneously.

Background of Third party:
This is the extension of the restriction mentioned earlier. The earlier point was about running an application on screen but this is about running an application in the background. This restriction does not allow any third party application to run in the background. This implies that when you are attending a call crucial for your business, you cannot collect any messages through the instant messenger. The worst part of this is that you are shown to be offline to the message sender. This could lead to a lot of misunderstanding and heavy financial losses.

Centralized Control:
No application can be directly accessed by the iPhone user. Every iPhone user has to download the application from the Apple Store. This implies that the developer has to first submit the application to the Apple Store and if Apple Inc. finds it worth distributing among the users, then and then only the application is going to be accessible by the iPhone users. This sort of centralized controls not only puts restrictions on the developers but also increases the chance of unnecessary delay in the utility of the application.

Version compatibility:
The application working on the latest version may not work on the earlier version. This is because the operating system of different versions may not be compatible. This is very crucial for the application developer because he/she has to finally test the application on two versions of iPhone operating systems.