This tool has been developed to assist readers of the paper “Explaining spatiotemporal dynamics in lambda-omega reaction-diffusion equations using absolute stability spectra of wavetrains”—written by Matthew J. Smith, Jens D. M. Rademacher, and Jonathan A. Sherratt and submitted to “Physica D: Nonlinear Phenomena”—in understanding the numerical dynamics illustrated and to encourage readers to experiment with changes to boundary conditions and parameter values.