I'm not the developer, but as I was looking for some calculator/conversion apps (as I'm an engineering student in college) I stumbled upon... [app]Quick Graph[/app] Wish I would have had this in my calculus classes as it would have made the graphing homework problems a lot easier. Got it anyways to play around with it, and I'm very impressed. It can produce 3-d graphs and has a really easy input system. Oh, and it's free. Edit: Also, I've been a visitor to Touch Arcade for some time now, but this is first post. Sorry if I'm breaking any forum rules or duplicating some common knowledge.