droidplotBy Corbin Champion ( Free )
gnuplot running on android.Need ATE (android terminal emulator) installed before you install this to work - https://play.google.com/store/apps/details?id=jackpal.androidterm&feature=nav_result?t=W251bGwsMSwxLDMsImphY2twYWwuYW5kcm9pZHRlcm0iXQ..Can be used standalone like gnuplot, or used by octave as its plotting engine. https://play.google.com/store/apps/details?id=com.octave&feature=search_result?t=W251bGwsMSwyLDEsImNvbS5vY3RhdmUiXQ..