We originally covered the kind-of-ridiculously-awesome MyScript Calculator last year back in July, but it's received a significant update today that should have you checking out this amazing app if you haven't already.
The premise is simple: write out your math equations just like you would on paper, and presto-amazo, MyScript converts them to text and solves them. Now, though, it does even more. Like portrait mode, which is sort of a weird thing to just now get around to adding (eh, eh?), but at least it's there.