I can’t find the original pin, but ONE DAY after I saw the pin (no words needed), my youngest had the strap of her flip flop come out. I now present
the flip flop fix-it

“I” of GAIN reports that she can feel the tab through the sole of the flip flop, but that it is not annoying.
I just got this in an email! Love love love it…will extend the life of my $1 flip flops that much longer!