Solitaire puzzle: The towers

Solitaire - The Towers : A unique incarnation of the Solitaire game.

"Patience, or solitaire as it is known in the US and Canada, is a genre of card games that can be played by a single player. The purpose of patience generally involves manipulating a layout of cards with a goal of sorting them in some manner. It is possible to play the same games competitively (often a head to head race) and cooperatively." [source: wikipedia]

FEATURES:
- three levels of difficulty (easy, normal, hard)
- support local and global leaderboards (with google play services)


Rules

Goal:
To build up an ascending sequence of cards of the same suit (straight) upon four Ace foundations and to build up a descending straight upon four King foundation piles.

Moves inside the tableau:
- a player may move only the upper card from the pile to build up kings or ace foundations.
- in case, a tableau cell is freed up (there are no more cards in a deck), any card may be moved to that free cell

The stock:
- by clicking the stock, the topmost card is moved to one of the decks in the tableau, with the position that equals the clicked card’s value (i.e. a corresponding to the first deck in the tableau, 2 corresponding to the 2nd, and so forth) and the affected deck will unfold at the bottom of the screen.
- the position of cards in the active deck may be freely changed
- by clicking the card-icon, the active deck returns to the tableau

Piles of Kings & Aces
- cards may be moved back and forth between the piles of Kings and Aces.


Difficulty:

EASY - in addition to the rules above, the player can have a look under the topmost card (plus help is available)
NORMALl - all the above rules apply
HARD - the above rules apply with the exception of free card moving between the piles of Kings and Aces