A lot has happened since 2007. Just look at how much the iPhone home screen has changed. Or how little it has? Back in the days of the first iPhone (it wasn't even called iOS yet), we couldn't get third party apps or even move apps around. Now, we have a bigger screen and all these funktastic icons.
It is impressive to see the consistency (or is it stubborness) that Apple has had with the iPhone home screen. Reddit user iKurac cooked up this graphic* to show the gradual additions and slow evolution of iOS over the years. Up until iOS 7, it's only added new apps. But after iOs 7 gets released later this year, iOS 1 to iOS 6 will be part of the ancient era of iPhone. Something that'll be buried in a time capsule next to Android 1.0, Blackberry, Palm and Windows Mobile.