Sketching Idea is an addon for sculpting in Blender. When you're stuck on a sculpt with a couple of good ideas in your head, sculpting each one individually takes time and effort. With this addon you can quickly sketch those ideas and then sculpt the best one.
A distinctive part of the workflow is that a sketching stroke vanishes from the view according to your camera angle. The tool is opened with the shortcut SHIFT + CTRL + A, and it's built for Blender 2.8. The addon is released under the GPL license.
Sketching Idea is listed as free here in the catalog, with the option to support the project through a purchase on the developer's page. Documentation is included with the addon, and a demo video is available if you'd like to see it before installing.