If you haven't been keeping an eye on Wolfram, makers of Mathematica, you're making a mistake. They've been extremely active making math apps for iOS recently. First, there was the Wofram Alpha app. Fortunately, they cheapened that up quite a bit after their initial mistake of charging almost $50 for it (now costs only $2). Now they have out study guide apps to help with math and science courses, all the way up through college. Where are they headed next with this? Who knows, but it'll be fun to watch.