We need at least one large app icon:
"A large version of your app icon that will be used on the App Store. It must be at least 72 DPI, in the RGB color space, and 1024 x 1024 pixels (it cannot be scaled up). The file type must be .jpeg, .jpg, .tif, .tiff, or .png. It must be flat artwork without rounded corners."
So what is the app all about? It's a very simple gas consumption tracker. You simply enter your refills, their price per liter, and optionally the current value of your odometer, and it does the rest for you :)
We need at least one large app icon: "A large version of your app icon that will be used on the App Store. It must be at least 72 DPI, in the RGB color space, and 1024 x 1024 pixels (it cannot be scaled up). The file type must be .jpeg, .jpg, .tif, .tiff, or .png. It must be flat artwork without rounded corners."
On the way, we should make icons for the device, and why not a launch image as well. https://developer.apple.com/library/ios/documentation/userexperience/conceptual/mobilehig/IconMatrix.html