Sevens, developed by CatTama, is a free card game available on Android. It falls under the subcategory of card games and is a single-player game played against three computer opponents. The objective of the game is to play cards in order and be the first player to clear all the cards in hand.

The game starts with each player being dealt 13 cards and submitting the 7 number card from their hand to the central field. The player who submitted the 7 number of Diamonds card starts the game, and the game proceeds in clockwise order. The game ends when all the cards in hand are submitted to the central field. Players can pass up to three times, but if they pass four times, they lose. Losing players' cards are automatically arranged in the central field, and players who successfully clear the game receive points according to their ranking.

Overall, Sevens is a deep card game with simple rules that are easy to understand. It's a great option for those who enjoy card games and want to test their skills against computer opponents.