Launch the app and select 'Play' to start a new game. Follow the interactive tutorial to learn the basics: draw one card from the deck or discard pile, then discard one to reduce your deadwood. Aim to form melds (sets of 3-4 cards of the same rank or runs of 3+ cards in sequence of the same suit) and knock when your deadwood is 10 points or less, or go for Gin with no deadwood.