Brain Trainer: numbers game 1.5

Train your brain with this very addictive game. Three board sizes, three game modes and three graphic themes available!
Test your intelligence :)

/*** How to play ***/

Swipe your finger to move the tiles.

- POWER OF TWO: when two tiles with the same number touch, they merge into one. For example, 2 merges with 2 and becomes 4, 4 merge with 4 and becomes 8 etc.

- POWER OF THREE: when three consecutive tiles with the same number touch, they merge into one. For example 3 merges with 3-3 and becomes 9, 9 merge with 9-9 and becomes 27 etc.

- FIBONACCI: a tile can be joined with a tile that is one level above or below it but not to one equal to it. In Math, Fibonacci sequence is a succession of numbers in which each number is obtained by adding together the last 2 digests that came before. The first terms: 0-1-1-2-3-5-8-13-21-34-55-89-144. For example 2 and 3 merge together and become 5, 5 and 3 merge together and become 8 etc.

Inspired by Gabriele Cirulli game available on the web:
http://gabrielecirulli.github.io/2048/

and by the Danqing Liu's opensource code available on the web: https://github.com/danqing/2048