Xcode

If you want to create apps for apple products like iPhone, iPod Touch, iPad, etc, then you can use Xcode.

Xcode is an Integrated Development Environment to create apps only for apple products.

You can create a prototype of user interface with Interface Builder feature, so you don't need to code to create it. But if you want to build a fully working app, you need to know how to code.

All images from :
apple