Sudoku FV app for iPhone and iPad

The objective is to fill a 9×9 grid with digits so that each column, each row, and each of the nine 3×3 sub-grids that compose the grid (also called "boxes", "blocks", "regions", or "sub-squares") contains all of the digits from 1 to 9. The puzzle setter provides a partially completed grid, which for a well-posed puzzle has a unique solution.
To put the figure, the figure is moved to the cell with the drug.
The cell is changed, and moreover, the memo is changed when touching and the accessory and the color can be changed.
The problem can be made besides the problem is solved, and the answer of the problem be derived.
There are five stage difficulty of the problem. The number of problems has 2000.