iGraphmatica!

Graphmatica is a powerful, easy-to-use, equation plotter with numerical and calculus features:- Graph Cartesian functions, relations, and inequalities, plus polar, parametric, and ordinary differential equations.- Data plotting and curve-fitting.- Up to 999 graphs on screen at once.- Numerically solve and graphically display tangent lines and integrals.- Find critical points, solutions to equations, and intersections between Cartesian functions.- AutoSquare keeps your graphs from getting squashed as you zoom or enable helper panes; or disable it in General Settings so you can scale each axis independently by pinching horizontally or vertically.- Print your graphs, copy to clipboard or export to Photo Album.- Share graph documents with friends or Graphmatica for Mac or Windows via email or iTunes.- Online help and demo files make getting up to speed a snap. In summary, a great tool for students and teachers of anything from high-school algebra through college calculus.