Based on your criteria I think you’d enjoy checking out my newly released Uni Sudoku for the iPhone/iPod Touch. For several years I’ve sold a popular Mac application that is now an iPhone app. I believe the only criteria in your list not satisfied is unlimited puzzles. There are 100,000 in Uni Sudoku. First, I challenge you to complete that many, second I challenge you to remember puzzle 1 when it comes around again after 100,000.

More seriously, by not including my puzzle generator in the iPhone app I’m able to make sure all of my puzzles satisfy my criteria for being interesting and appropriately rated. Finally I update the puzzles list when I submit a new update.

If you do check it out I’d love to hear any feedback you have.

Best,
Dave

I hope there’s a way to build up a cache of sudoku. For example, you could load an entire book of sudoku into the phone before a trip, in order to play the contents of the book while in transit.

I would also suggest using the solver to check puzzles, if possible. At the least, it could only present the “please check the puzzle” screen if the solver can’t find a solution to the puzzle as initially scanned; even better would be if your recognizer can provide alternate numbers to try.

The next updates will be all about improving the puzzle playing interface – I’ll definitely be using your criteria to drive that.

Cool.

Have you had a look at Sudoku Grab? I put it on the app store a couple of weeks ago.

I don’t know if it covers all your criteria – it doesn’t have a puzzle generator. What it does have is the ability to take a picture of a puzzle and then play it on your phone! It’s really cool (even if I do say so myself).

The UI is pretty clean. I’ve just submitted a new update – should be live sometime next week that adds a lot of new features.

The next updates will be all about improving the puzzle playing interface – I’ll definitely be using your criteria to drive that.

Cheers
Chris.

Thanks for all your effort. I posted a review of ACTSudoku here on my blog, as well (a few minutes before seeing your latest comment here, actually).

ACTSudoku has been dragged down by negative comments. Most by people to dumb to read the description which tells them

- to use long taps to commit a value
- go to the Settings application to switch off negative markers

Best,
Pierre Bernard
Houdah Software s.à r.l.

Best,
Pierre Bernard
Houdah Software s.à r.l.

I am baffled how this can be so popular with customers. It falls short on my no. 1 criterion for a Sudoku game: the boards are not solvable by logic. They require guessing and backtracking. IMHO this is just unacceptable. Instead of a Sudoku generator, one buys a plain random number generator!

P.S: ACTSudoku 1.1 is in the hands of Apple’s reviewers…

Best,
Pierre Bernard
Houdah Software s.à r.l.

I am about to wrap up development on an update to ACTSudoku.

It adds rotational symmetry!
It also adds a bookmarking feature as well as the ability to start over with a given game.
The interface has also been fine-tunes.

Did you get a chance to try ACTSudoku? I’d love to hear your feedback.

P.S: Apple is currently very slow in pushing updated applications to the App Store. I have no idea when the new version will become available for sale. But it will be a free update.

Best,
Pierre Bernard
Houdah Software s.à r.l.

Nikoli argues that this changes (they would say improves) the gameplay, and I don’t disagree with them. Of course, we should keep in mind that they sell their own sudoku, including one of your competitors. ☺

The concept of rotational symetry is interesting. I’ll see I’ll add it as an option in an update.

How come you like this so much? Are there any advantages to solving such a puzzle? Or is it just a matter of taste?

Best,
Pierre Bernard
Houdah Software s.à r.l.

It’s also one of the few that generates rotationally-symmetric puzzles.

Patrick: Postfix doesn’t bother me. I prefer it, actually. I like RPN, too. ☺

Yes, rotational symmetry applies to the given numbers. Those are the black cells in the diagram.

Pierre: I did like ACTSudoku‘s input method (which I thought similar to the ring of numbers) based on the screenshot, but I’m more dubious after watching the screencast. It’s more complex than it looks. I suggest swapping number-placement and pencilmarks, so that changing the number color is what takes the longer tap. That said, I’m willing to give it a shot the way it is.

More importantly, ACTSudoku does not generate rotationally-symmetric puzzles. All other forms of symmetry don’t count.

I am the author of Houdah Software’s ACTSudoku for iPhone. I believe you are going to love it.

1. A sudoku generator: CHECK: virtually unlimited fresh games, not plain transformations applied to existing boards
2. ACTSudoku generates symetrical puzzles. They are symetrical along one axis: horizontal, vertical or diagonal
3. Obvious input method: Watch the screencast at http://www.houdah.com/iPhone/screencasts.html I think you’ll like it
4. The ability to set pencilmarks: CHECK: ACTSudoku calls them markers. OPTIONALLY, ACTSudoku may help you by automatically blocking excluded values. Great at higher difficulty levels
5. Simple, usable interface: Matter of taste. I say CHECK

Best,
Pierre Bernard
Houdah Software s.à r.l.