Insensitive (Incredible Nuclear Spin EvolutioN SImulation Tool Intended for Visual Education) is an application to simulate the NMR experiment based on the quantum mechanical density matrix formalism. It is available for Mac OS X 10.6 and above and iOS 5.1.1 and above. Please refer to the paper published in Concepts In Magnetic Resonance, 2011, 38A (2), 17-24.