A variety of organisms employ Latch Mediated, Spring Actuation (LaMSA) to achieve velocities, accelerations, and power outputs unmatched in either directly actuated muscle-driven systems or synthetic systems of a comparable size and repeatability. Previous efforts to model the mechanics of LaMSA systems have assumed linear constitutive relations for the system elements (spring, latch, and loading motor). We present a simplified “toy model” of LaMSA systems, and an associated open-source software package, that allows for the selection of different nonlinear forms for the constitutive equations of each element. The graphical user interface associated with our model also allows users to plot performance metrics across one- or two-dimensional cross-sections of the overall parameter space. This tool allows us to determine parameter space regions in which a LaMSA system is more effective than a purely motor-driven system. The nonlinear capabilities of the model allow us to better probe the properties of LaMSA systems than might be possible with linear models.