Bag-O-Loot, self-published by John Shelley, is a mix of rummy and Bull****, with some Steal the Old Man’s Bundle thrown in for good measure.

Lay down pairs, add to your piles, or steal other players’ piles. Add a fifth card face down to cap a pile, where the face down card is supposed to be the same value as the values in the pile, but you can bluff. Players may opt to challenge you.

Cute, but the designer apparently spent as much time patenting the game as he did designing it.

(source)