Letter Mind

Letter Mind is a logical game similar to Bulls and Cows, Mastermind or Jotto.
Gameplay consist of guessing a secret word in a number of tries.
A player has to provide a guess word and it will be evaluated with number of
correct letters in wrong positions and with number of correct letters in right
positions. This information should be used to identify the full set letters
in the secret word and their positions.
Preferences allow to change length of secret word and the set of allowed letter.
With word length of 4 and 10 letters allowed the game is equivalent to the Mastermind.
In helper mode the application does self deduction and supply the player with guesses.