Have you ever walked the street wondering what's nearby or just around the corner? The City Lens app from Nokia fits into a category called "augmented reality" apps and it's designed to help you find things you don't yet know about.
Nokia's City Lens app allows you to point your phone camera in a particular direction and it will overlay on your screen the names of restaurants, bars and stores that are nearby. It automatically adjusts as you move or turn in different directions. It's probably most useful if you're wandering around in a new area.
The main limitation of the City Lens app is that it is only available for Nokia phones using the Windows Phone software. Nokia is using this and several other apps such as Nokia Drive as a carrot to entice people to buy one of their smartest phones. Quite a tasty carrot, I might add.