The rapid deployment of 5G New Radio (5G-NR) networks worldwide and the expected expansion in the coming years demands accurate planning tools to address the challenges of high-frequency propagation in complex urban environments. While commercial simulators provide detailed analyses, their high cost and limited customization hinder accessibility for academic institutions and research laboratories. This paper presents the development of a cost-effective and flexible 5G-NR propagation simulator based on Ray Tracing, implemented in the Unity game engine. The tool enables realistic modeling of signal propagation, accounting for interactions with environmental elements such as buildings, streets, and other obstacles. Validation was carried out through a measurement campaign at the Faculty of Informatics and Electronics at ESPOCH for frequencies up to 20 GHz, comparing simulated results with real-world data. The simulator achieved an average difference of 5.19 dBm, demonstrating its capability to model propagation with high fidelity. Additionally, the Unity-based environment supports real-time interaction, allowing users to navigate the 3D scenario and visualize direct and reflected rays dynamically. This open and adaptable solution offers a valuable alternative for network design, optimization, and education, bridging the gap between costly commercial platforms and the needs of research and training in emerging 5G technologies.