Bones is a solo ttrpg that fits on a business card.
You need a 4-side die, a pen, and paper to play.
This game was originally "published" in a tweet. It can be found here:
https://twitter.com/junkfood_games/status/1573349790393540608?s=20&t=0TPsRQQByT_...
Price:
$1.00
Rating:
4.80 (from 6 reviews)