To support post-processing of CST Studio Suite results from the Wakefield and Eigenmode solvers, an existing modular MATLAB workflow is extended with graphical user interfaces developed using MATLAB App Designer. The goal is to develop MATLAB GUIs (App Designer) that provide a unified and user-friendly interface for routine analysis (import, evaluation, visualization, export). The implementation will follow clean-code principles and will be complemented by an automated test suite that verifies selected outputs against analytically solvable benchmark cases to ensure long-term reliability and reproducibility.