This game is free, with no advertising and non intrusive.

Sprouts is a two-player game. You can play against Android.
The game starts with a few spots drawn on a sheet of paper. Players take turns, where each turn consists of drawing a line between two spots (or from a spot to itself) and adding a new spot somewhere along the line. The players are constrained by the following rules:

-- The line may be straight or curved, but must not touch or cross itself or any other line.
-- The new spot cannot be placed on top of one of the endpoints of the new line. Thus the new spot splits the line into two shorter lines.
-- No spot may have more than three lines attached to it.

The player who makes the last move wins.

In this version of the game, Android can not draw the lines. At android's turn, it scores 2 points with the colors green and yellow (or a single point with the 2 colors).
The human player must draw the line by joining the yellow spot to the green.

This game was invented by mathematicians John Horton Conway and Michael S. Paterson at Cambridge University in the early 1960s. Setup is even simpler than the popular Dots and Boxes game, but game-play develops much more artistically and organically.