IT's fully free, except for AD banner.
As a variant of hexa game, how to play is very simple.
Just make a horizontal, vertical or diagonal line with over three stones in the same color
and if you succeed in it, they will explode themselves and all over them will fall down.
A removal : +1 (so you will get at least over 3 points.)
Removal of more than two lines at one dropdown: +50
Explosion of more than three times in sequence: times x 30
To move to left or right: Swipe (touch and drag)
To rotate: just touch down and release.
To fall down: just drag down.