iOS Simple Mathematics App

Hi, I need a simple iOS Mathematics Game, which would work as follows: It would start of with some addition / subtraction / division / multiplication / percentage operation, and prompt user to input an answer. It would then show up something like "your answer Times 2", and again, user input a number, and so on. Things I need: The App to remember high scores. The App making sure operations do not result in fractions. The App having 3 difficulty levels. The App to Time your attempts, Time per each Attempt, how many questions answered before mistake, etc.. The App to check answer and prompt if correct / incorrect before going forward with the next question. The App to have a basic design (nothing fancy). Please let me know how much this would cost. Additionally, can you let me know how much it would cost to have the user input answers through microphone / Siri style, as oppossed to typing them in.