A value-added, comination calculator, SciStatCalc combines the functionality of a dual calculator for scientific equations and statistical functions.
iPhone and iPad apps tagged "advanced mathematics."
SpaceTime Super Calculator for Advanced Math Functions
SpaceTime. A graphing and scientific calculator built on an advanced mathematics engine. It's not the kind of thing you need every day, but it is the kind of specialized calculator that you expect to pay dearly for when you do need it.