Write an iPhone application

This job is not to create an iPhone app just yet. This is to get some more information and to find someone we can work with to build an app for our web-based software. The site has a working database and full functionality (mySQL database and PHP based site) and we want to bring some of that to the app. I need to work with someone who has built an iOS app before and knows exactly what is involved. My business partner is a designer and would design all of the screens for the app, so I need to know from you what format these need to be in and how they should be presented to you. I understand it might be difficult but it would be helpful to know what sort of cost we are looking at to build the app. As I say, the screens will be designed for you. The app is for a proposal system that already exists. Users can send a proposal and they receive email notifications when it has been opened/signed. They can also view tracking for each page view. We want to bring this to the app so that the email notifications take on the form of app notifications, and it will display a timeline of all their proposal activity (i.e. when a proposal is sent/opened/signed). Please feel free to ask me any questions you might have or pop me a message if you want to have a deeper chat.