![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgk-MKPy-veuWARvEMTi0sV5_bjrwzREgtZFXy1pdvPS8IQ7ZypYl3KKh1NE9P5ySKd9-rr73L9TxCMky5K9td6KV9FMvP-Icsmnn4Qd4ymBXu4yaAFjYv-V4F5pkEwWhc3jxQup6B4Tojn/s320/Screen+shot+2011-02-17+at+7.20.24+AM.png)
I've put up the files for the Fifteen puzzle I posted about the other day (here). This is an Xcode project (and includes a copy of the built application). It's on Dropbox (here).
You can move tiles by clicking with the mouse or using the arrow keys (much faster).
I have not solved the technical problem of eliminating unsolvable puzzles, but I've played a few times and have yet to run into one. Either my expectations are wrong or I'm just lucky. I'll try to work more on this some other time.