Word Master Stack is a classic crosswords board game with a unique twist. This iPhone game, developed by Luis Gualandi, allows you to place letters on top of each other, adding a new dimension to the gameplay.

To play, you must build words on a gridded gameboard by placing letter tiles next to or on top of the existing tiles. Each turn, all tiles played must form part of one continuous straight horizontal or vertical line, and any new words formed in all directions must be valid. The height of the stack on which each letter is placed determines its score, so forming higher stacks will earn you more points.

The game offers several features to enhance your experience. You can play offline with four different difficulty levels or engage in a Pass and Play mode with friends. It includes a built-in word definition feature, allowing you to look up the meanings of words as you play. Additionally, after each turn, you can see which words you could have played, providing helpful insights for future moves.

Word Master Stack supports multiple languages, including English, French, Portuguese, German, Spanish, Italian, Dutch, Norwegian, Romanian, and Catalan. Each language has its own best word lists, ensuring a challenging experience for players of all backgrounds.

With its detailed stats, validation and scoring of words as you place them, customizable tile drawing modes, and hints feature, Word Master Stack offers a comprehensive and engaging gameplay experience.

Please note that the game is available for free, making it accessible to a wide range of players.