The Tomorrow Children is an adventure game for PS4 developed by Q-Games, and now it has a mobile game as well, which you can download on Android and iOS for free.
The Tomorrow Children: The App is a puzzle-oriented game, using the puzzles featured in the main game such as when riding the train. The puzzles revolve around a wooden board, and although the main game features co-op elements, the puzzle game does not.
There's also no connection to the main game either. Will you be downloading the app?