A free app for Android, by Crazy Jelly Fish.

Dots and Boxes Classic Board is a classic board game. You need to connect two dots to complete a line, and a player who fills a line will be the winner. It is one of the oldest and most popular board games. Players connect dots in the same way as in connecting two lines with a straight line, but the squares that they form can have various colors. There is a simple mechanic that allows you to form lines. 

It is very easy to play and there are a lot of possibilities to create new moves. Dots and Boxes Classic Board is a very addicting and fun game, you can play it for hours and hours without getting bored.