Hi,
Please try to check my portfolio and you will see I have experience designing iOS and android game. I need to know more detail about the game so I can give you exact price. It could be 200-1500 USD depends how much detail. I guarantee 100% satisfaction and will give you unlimited revisions until everything is perfect. You're going to receive a proper PSD file with layers. I promise it will be easy for the coder to work with.
Thanks,
Jay