KML Tools can be found in the QGIS menu under Vector->KML Tools and Raster->KML tools, on the tool bar, or in the Processing Toolbox under KML Tools. It has three vector tools and two raster tools. This shows the tools in the Processing Toolbox....
KML/KMZ import very quick. It adds the nested folder structure to a field in the QGIS layer which can then be used for sorting and filtering based on the folder structure in the KML. A KMZ can be exported with simple, categorized, and graduated QGIS styling for points, lines and polygon...