The most underutilized feature of the iPhone is that it’s always on us. Everywhere we go, it’s right there with us. Apps like Rewind will change that, as it’s focused on one job and does it extremely well. Rewind keeps track of how long I’m at all my important locations. This allows me to see where each second of my day goes, with actual numbers, and I doubt that I’ll want to live without these numbers now.