Sudoku Revolution: fee puzzle app for iphone, ipad

Sudoku Revolution is extremely well designed. In terms of the puzzles: there are the traditional sudokus, and the jigsaw sudokus (see the image on the left). And of course the X versions where the diagonals have that same sudoku property.

Here's what I particularly like about Sudoku Revolution: the chart at the bottom left indicates how many 7's & 9's etc are already on the board. If you tap on that chart  - let's say 1 - all the 1's on the board get circled.

Did I mention that Sukoku Revolution is free?