Download link and brief installation instructions is at Lights Off website.
I’ve always loved Lights Out game from Tiger Electronic and iPhone with touch screen couldn’t be any more perfect for Lights Out-type game. This game is freeware and you should use it at your own risk. I’m not going to provide detailed installation instructions here as it’s fairly complex but I will update this post with a link when there is one.
Edit: This instruction is pretty good iPhone Atlas â€“ 5-step process for putting apps on your iPhone