In dynamic measurements of Young’s modulus for solids, students often struggle to grasp the model and identify the fundamental resonant frequency. This paper addresses this by exploring the use of the finite element software COMSOL: Multiphysics (hereinafter referred to as COMSOL) in building digital teaching resources. Specifically, it presents the development of an App for analyzing the bending vibrations of prismatic and tapered slender rods. The App allows users to input geometric and material parameters, automating geometry creation and meshing. Using finite element analysis and post-processing visualization, it outputs key data of slender rods, such as natural frequencies (including fundamental and higher modes), nodal positions, mode shapes, and harmonic responses. A comparison of the simulated natural frequencies and nodal positions with theoretical values shows the simulation’s accuracy and reliability. The compiled App can run independently of COMSOL, aiding teaching and serving as a valuable reference in practical engineering structure design and vibration control.