γ-Cascade (also called GCascade) uses a semi-analytic approach to model gamma-ray propagation through cosmological distances accounting for attenuation, the formation of electromagnetic cascades,and cosmological redshifting. V4 implements an assortment of the most widely used EBL models, significantly improves computational precision, and provides new core functionality. Additionally, GCascadeV4 uses a new method to estimate the uncertainty due to the EBL model.