Simple one page app for geometrical calculation

I am looking for a person who can help me write a simple app that would perform a single trigonometrical calculation, based on user input. on the first page the app would present a 2d graphics, which I would provide, ask a user to enter two numbers, input those numbers into the trigonometrical formula and present the result on top of the page, right above the graphics. I think a single page application with HTML and java script would do it. I need the same thing to be done in two versions - Android and Iphone. NDA will be given upon project acceptance.