iOS additions in app

I have simple app in XCode (latest version) and it works fine. Application is quite simple and it has main screen plus help and about screen. I need to add following in app: 1. Support for portrait and landscape mode - How it should work? When user rotates device, background image display should look fine in both portrait and landscape. For this we can use two images, I think it can be done this way. 2. Support for devices (screen sizes) for 3 screens in app: -- iPhone 4, 4S, iPod Touch 4 960 × 640 graphics size A - iPhone 5, iPod Touch 5 1,136 x 640 graphics size A - iPad 1,2, mini 1,024 × 768 graphics size A - iPad 3,4 2,048 × 1,536 graphics size B To support it, we can have graphics (images) in 2 sizes, as above. Background images that covers whole screen (3 screens) must be for each size. I will provide all graphics. 3. Implement in app purchase to buy several items. 4. Rate app We will ask for user to rate app after some time (minutes) or have a button to rate app. We can implement this in other way, not needed to be like this. 5. add : Facebook Invite friends button Send email button We can discuss it in more details.