A free program for Android, by utachiwana.
BWT is a strategy card game, where your goal is to score as many points as possible. Each game is divided into several rounds, where in each round you play with the same opponent and use the same set of rules. The goal of each round is to score a certain number of points, by default 21. There are 28 different trump cards, which can be used to change the rules of the game, and to get a specific card from the deck, and so on.
There are 11 cards with values from 1 to 11 and no suits. Each round you play with the same opponent and use the same set of rules.