convert the game from windowsphone system to iPhone and the

I want to launch the game on store windowsphone and Apple I am currently developing a war game of the 16 stages, working on a windowsphone system. will be finished this month. So I'm looking for a specialized company/developer to develop games for iPhone to convert the game from windowsphone system to iPhone and the iPad. If you are able to do ,so please tell me the time and cost To correspond the game with system iPhone and the iPad. Important Note: The developer must be a previous work, a professional about games