LibrX is a VFX library for Blender built by Holapro. It ships as a collection of pre-simulated assets covering cloth, particles, smoke, fire, explosions, curtains, and lights, so the simulation is already handled within the package. The developer describes it as easy, light, and fast to render.
The add-on supports Blender versions 4.0 through 5.1 and is listed as a compatible Blender extension. Its assets are built for both the Cycles and Eevee render engines, and the package ships under the GPL license. Documentation is included.
LibrX is listed here as free, and a demo containing free assets from each category is available. A demo video can also be found through the developer's page. For current licensing terms and the full package details, refer to Holapro's page rather than relying on the summary here.