I'm stumped. All of my iPhone apps are up-to-date, and the Applications window in iTunes doesn't indicate that any two apps are in any way different than the others. So what does that 2 mean? And how do I make it go away?
What does this mean?

I'm stumped. All of my iPhone apps are up-to-date, and the Applications window in iTunes doesn't indicate that any two apps are in any way different than the others. So what does that 2 mean? And how do I make it go away?