Purcellion stands out as a purpose-built scientific tool that merges precision with simplicity, offering researchers and students an intuitive way to explore quantum cavity dynamics. Unlike generic calculators, it is tailored specifically for quantum dot and nanophotonics applications, providing real-time insights into Purcell factor behavior, emission rate enhancement, and cavity volume-to-Q scaling. Its elegant interface, gradient visuals, and built-in input validation ensure accurate results while maintaining a smooth user experience. By combining advanced physics formulas with user-friendly design, Purcellion helps bridge the gap between theory and practical analysis, making it an essential companion for anyone studying or designing nanoscale optical systems.