I got a link through GitHub to a more updated version on RetopoFlow; works better now. Gee, I hope they can somehow put that in the Blender Market. Seems like anybody can access that right now.
Anyway, I’m using a practice mesh and trying out contours, and PolyPen for getting into the inside details. I just need to remember that retopology class to figure out what I should do to best close the retopology.

Oh, @blanchsb , I confirmed that link on GitHub that I mentioned above, where the shift + middle mouse wheel seems to work now in decreasing the face count. I let them know in that issue. I’m glad I found that post, too! I was going to post the issue, myself! I’m nervous posting things on GitHub. I’m shy. Ha ha!