I vote for the same, but I thought they were Jiffy Hangers or Patton Hangers or Madison Straps.
I'll add the sixth or seventh vote for the Madison Strips.
And as for their name, I've always known them as EZEins (pronounced "easy ins").
I like that the push-pull receptacle use forces are confined in a straight line through the drywall between the plaster ear and the EZEin. In both the U-grip and tiger grip the push-pull force is in a diagonal through the drywall. The longer the lever, the greater the force on the drywall.
Have to say, until Mark's comment about masonry, I didn't think there was any use at all for the "tiger grips".
And, in my opinion, the key to an installation that withstands heavy receptacle stresses is to carefully cut to leave the greatest amount of undisturbed wall under the plaster ears and to pull up the EZEins snug with no looseness. . . . That said, if the forces are going to be truly heavy, mounting beside a stud and using an entirely different type of box is the only solution.