Does anyone remember a little device that would attach to the
your front down tube and swing down to hold the front tire in
place if you were leaning bike against something.

it was made out of plastic (bracket that attached to tube and arced part that interacted with tire tread.
They were attached by spring steel.

Different sizes for variety of tires.

The last one I bought was about 20 years ago.

I'm looking for a name or a source. I thought they were a great idea.