The app, step by step. The rules are on their own page; this is what you'll see and what to tap.
Someone deals a game and picks Koum-kan on New game (two to six of you). Say Deal me in; the table deals itself when everyone has answered.
The strip at the top counts everyone up from 20. The pile and the stock sit in the middle; whatever's been put down goes above, under the name of whoever put it down. Your ten cards are at the bottom.
Tap the stock to draw, or tap the top card of the pile twice to take it.
Tap three or more cards that make a set or a run, then Put down. Once you've put something down, tap one card and then a glowing set or run to add it there. Tap a card and Discard to end your go.
Holding two cards with a discard to come? Tap Say Carte! first. If someone else forgets, a Catch! button lights on your phone — tap it before the next go is played and they pick up three.
When someone goes out, the feed says what everyone was left holding and the next round is dealt straight away. At 0 you're out and can watch. The last one standing gets the crown; Rematch deals the same table again.