This is good!

You can enter your own games and or play one provided!

This has advanced features which allows you to detect Wings and Chains etc. This is not as sophisticated as Sudoku Susser but the interface is much better looking.

I have not found out how to get it to tell you that you have entered a wrong entry and this is probably the only thing missing.

Having said that, it is definitely worth the download.

NOTE that if you're not an advanced player you'll probably find it too heavy but if you know what Sudoku is all about, try it out!