STU48の7ならべ is the official game app of the regional idol group STU48, which is based in the Setouchi area and spans seven prefectures. The game's objective is to increase your intimacy level with your favorite group member by playing the card game 7-Narabe. As you progress and raise your intimacy level, you can unlock new features such as card awakening and secret message sharing.

The app features a CPU mode where you can play against the computer and an online multiplayer mode where you can compete against other players. In the online multiplayer mode, you may even get the chance to play against the STU48 member themselves! The game is easily playable on your iPhone with its vertical screen and card assist display.

Note that the app offers a Gold Pass subscription that allows for automatic heart regeneration at a rate of one per 30 minutes. The subscription is priced at 480 yen per month and can be canceled within the first two weeks of purchase.