"4 in a Row" is a highly addictive board game that tests your strategic skills. Developed by Ultima Architect Inc., this game is available for Android devices and has over 3 million downloads worldwide. It is easy to learn but hard to master, making it a great game for all ages.

The game features three modes: 1-player (Human vs CPU), 2-players (Human vs Human), and Watching mode (CPU vs CPU). The game also has ten levels of difficulty, a scoreboard and rating system, and supports undo and hint functions. Additionally, it has other various options such as CPU Level Auto-matching, Alternate first move, and support for tablet size devices.

The game rules are simple - each player takes turns dropping one of their discs down any of the slots in the top of the grid. The play alternates until one of the players gets four discs of their color in a row, either horizontally, vertically, or diagonally. The first player to get four in a row wins. If the board is filled with discs and neither player has four in a row, then the game is a draw.

Overall, "4 in a Row" is a fun and challenging game that will keep you entertained for hours.