Puzzle games are a great way to kill time and exercise your brain in one fell swoop. They challenge you to think strategically and plan ahead, whether that's to create killer chain combinations for maximum points, or to plain old keep from getting killed.
Overall, iOS is more impressive than ever with its stability enhancements, security tools, suite of apps and services, and intuitive user interface. With each passing update, things just get better and better for iPhone users. But don't think for a second that this is all because of Apple's genius — many of these features were at least partly inspired by tweaks made by the jailbreak community.