Ripple Effect comes from Stanley Lam: http://brightskygames.com/
It is not Sudoku. It is not a Latin Square.
Each colored region must be filled with numbers in sequential order. For example, if a green region has 6 squares, it must use the #s 1-6. Any order will do.
There are 50 puzzles. A good mixture of easy, medium & hard puzzles and different grid sizes.
I like this!