Preparing a full description my first iPad App

As you know, I'm in the process of creating my first iPad app. My current goal at this moment is to create a well documented application description which will state the following:

• Application goals: why the application exists?
• Design principals: what is behind the choices that will be made in designing the application visuals and interaction metaphor?
• Interaction metaphor: a ten thousand feet above the ground description of the application interaction metaphor.
• Application features: what the user will be able to do with the application?
• Visual details: details, details and details about the application's visual elements.

The goal is to have a very complete application description that could be given to any iOS developers and designers so he could start building the application right away. My next blog post on the subject will be to provide each portion of this description. Stay tuned. 

By the way, I'm following this very good article: From Idea to Market: How we built Gradient.