Sudoku editor/Solver

[Han]

Very cool!

Some minor bugs and suggestions:

[Bug] Press solve. After solving, press the Help menu option, and then press a button or tap the screen for invalid input error.

[Suggestion] Perhaps the pre-filled values should be in bold. And bold the lines that separate the "blocks" of numbers to make it easier to read a block within the puzzle. Lastly (though it may slow down the solver), having the solver use a different color as it tries out various guesses would help. Even printing its intermediate guesses would help in cases where the puzzle is large. Otherwise, the user may think the program has "hung".