I came across something pretty cool the other day in iOS 6 that, once again, shows just how much time and thought Apple put into the OS.
One of the smaller new features of iOS 6 is the the Music app now includes a button in the upper-left corner that takes you to the iTunes Music store.
When you tap on a album, artist, or song, a back button takes the place of that store button — as is usually the case throughout iOS.
The difference with the music app though is that it is normal for you to be a few levels deep in the hierarchy. For instance, at any given point you're probably on the "Now Playing" screen, inside of an album, inside of an artist, inside of the music app. When you want to change what you're listening to you tap the back button in rapid succession until you arrive back at the main view of the app — the view where there is a store button where the back button just was.
Here is the cool part: if you accidentally tap that store button after having just tapped the back button a bunch of times, it won't work. It won't switch you out of the Music app and into the iTunes Store. Instead, it will just depress and do nothing. Since you probably didn't mean to tap the store button, and instead only tapped it because you didn't realize you didn't need to tap back again, Apple programmed the button not to work in that scenario.
Of course, if you wait a second and tap the button again it will work just fine — just as it usually does. But the fact that the button doesn't work in a scenario in which you probably didn't mean to tap it shows just how much thought went into iOS 6. Even the people that it helps probably don't realize what just happened. Only Apple would even think to do something like that when adding a new button to an app.