The objective is to fill the grid with numbers from 1 to 9 in a way that the following conditions are met:

1. As with classic sudoku: each row, column, and nonet contains each number exactly once.
2. The sum of all numbers in a cage must match the small number printed in its upper left corner.
3. No number appears more than once in a cage (this rule may be cancelled as an option).

Features:

• Sum-Sudoku and Classic Sudoku in 1 game.
• 4 levels of difficulty for both games.
• Save/Restore helps you to try out alternative ways.
• Undo/Redo with virtually unlimited levels.
• Show conflicts.
• Highlight digits.
• Best times table.
• Easy touchscreen operation with drag & drop.
• Help screen shows solving strategies.

On Classic Sudoku:

• Mark up candidate numbers, or...
• display automatic candidate list...
• and choose subscript or dot notation.