Dueling Mobile is a free Android app developed by Dueling Mobile that provides a simple way to build decks and test them online for the Yugioh trading card game. Although still in its development phase, it offers features like online dueling against other players, single player deck testing, and in-game siding and rematch functionality.

The app has a drag-and-drop/button system to play the game and allows players to reset the game for a rematch or side out cards to simulate actual match play. The deck building process is also very simple and quick, allowing users to search for a card name and tap where they would like it to go.

Dueling Mobile does not require an account and is rated for 12+. However, the developer warns that the card images may not be appropriate for younger audiences. Additionally, the app has not been tested much for tablets, so formatting may not be correct.

Overall, Dueling Mobile is a great way to play Yugioh on the go or when you don't have physical cards with you. The developer encourages feedback and patience as the app is still in development and may contain bugs.