A new app, freely available for Windows computers, has been developed to simulate tuning of an inductively coupled plasma mass spectrometer, on the basis of optimization data collected using a sector-field instrument. The app allows students to adjust parameters, including the torch position, gas flows, radio-frequency power, and guard-electrode state, while observing the signal for three "measured" variables in real time. The app has been used with a group of second-year undergraduate students to supplement theoretical material taught in an Atomic Spectrometry lecture course. The exercise familiarized students with key components of the instrument and demonstrated how multiple factors may need to be balanced when performing optimization.