I can't find any pictures but my flying buddy and I both use stooges that use a padded "U" shaped piece that hinges up to capture the horizontal stabilizer. Pull the string, the "U" falls down, and the plane goes. His is just made out of PTFE, piano hinge, and string -- mine uses light tubing for the "U", and wire to retain it. His is more universal, cuz when the "U" is down there's no obstacle to a tail wheel, while the top of my "U" sticks up about an inch or so -- so if I want a really smooth takeoff for a taildragger I need to use my other stooge.
I've found that on grass, my stooge doesn't get pulled around by the plane, but I do have holes so that it can be nailed down with tent stakes.