Quadoku Solitaire

Quadoku is a variation of Shidoku (Sudoku on a 4x4 grid), with the normal rules of Shidoku/Sudoku applying. The game can be played with the Ace's through Four's of an ordinary deck of playing cards, with the same restrictions on number placing also applying to the suits of the card deck.

The App has three modes of play:
A "Classic" Solitaire version where the player builds the grid from one dealt card,
An "Easy" Puzzle where the player solves the grid with 5 cards given,
An "Expert" Puzzle where only the minimum amount of clues are given.

The user may opt for Jack-Queen-King-Ace deck of cards if preferred.
Points are awarded for each card played, based on speed and accuracy.
There is an 'UNDO' button, but there is a penalty for using it. The puzzle versions allow the user to quit-and-solve, but doing so counts as a loss.
A grid that was started but abandoned is scored as a loss.
Switching to a different version or reloading before any card has been played has no effect on the statistics.