Functy is described as '3D graph drawing package. It allows Cartesian, spherical and parametric curve functions to be plotted and altered quickly and easily. This immediacy and the vivid results promote fun exploration of 3D function' and is an app in the Education & Reference category. There are six alternatives to Functy for a variety of platforms, including Mac, Windows, Linux, Online / Web-based and Android. The best alternative is GnuPlot, which is both free and Open Source. Other great apps like Functy are Grapher (Free), GeoGebra Graphing Calculator (Free, Open Source), Graphing Calculator (Paid) and MathMod (Free, Open Source).
Graph functions in two, three, and four dimensions, explicit, implicit, or parametric. Graph inequalities, contour plots, density plots and vector fields. Use rectangular, polar, cylindrical, or spherical coordinates. Solve equations numerically, graphically, or symbolically.