https://play.google.com/store/apps/details?id=com.maslak.touchGrapher touchGrapher is a graphing calculator which lets you draw graphs of many functions at once, manipulate them after they have been drawn and customize their appearance. Silky smooth experience due to full hardware acceleration on ICS+ devices. A function can be added by entering its formula, or by entering a finite number of points, so the function is created using linear regression, exponential regression or polynomial interpolation. You can also search for the functions' zeros, local extrema or intersection points with another function. The plane can be panned freely and zoomed using multitouch.