Very good

I have absolutely no problems with this app. Its worth noting that I did buy the full version because I hate ads and wanted more than just the easy level. There are six levels total: easy, medium, difficult, hard, diabolical, and evil. I havent touched the diabolical or evil since hard takes me an hour.
Its nice to see your time averages and best times to see if youre improving.
Just for people who dont want to upgrade.
The only thing that made me shrug my shoulders was that it no longer syncs between my iPhone and iPad. But it is an older phone and I still have all the capabilities that I do on my iPad.
I think its worth it to just buy the app if you spend as much time as I have playing.

Notenoughinfo about Sudoku ′, v3.3