Article footnote mentions this with the caveat that it requires some dexterity that young children may find challenging. That aside, I think the two games make a great complementary pair and switching between provides a nice contrast for kids.

You play normal one card poker until the kids realize the benefit of seeing other player’s cards - then you play blind man’s and learn that incomplete information can go the other way.

I suppose you can simply hold your card in your hands with the back facing you. Or use some kind of vertical holder.