Quick Decal is a Blender add-on for adding decals to your models. Rather than adding extra geometry, it uses a controller empty and blends your existing material with the Quick Decal material to place each decal. It supports multiple objects and materials, and runs in both the EEVEE and Cycles render engines.
The add-on sits in the texturing stage of a Blender project, keeping decal placement part of your material setup. It supports Blender versions 3.6 through 5.1 and is a Blender-compatible extension, released under the GPL license. Documentation is provided, and a demo video is available.
Published about two years ago, Quick Decal has recorded 90+ sales and holds a rating from four reviews on Superhive. B3dHub is listed as a Blender Development Fund contributor. For current licensing and the latest details, check the developer's page.