My F12 doesn't have Apps, but my F20 has. There are two features within it that I like:
The one I use every day is the internet radio, giving me access to the whole world. Since I tend to get bored of my own downloads on iPhone or iPod after a while, I love streaming the music directly in the car. Menues and search oportunities are very good, and your favourites can be stored under the preset buttons.
The other feature is Wiki local, giving you information on almost every building or attraction in the area. Since I didn't know about this before I got it, I was surprised about the overwhelming info. Not really a necessary feature, but cool.
To me the internet radio alone justifies the price. I've got the media craddle in both cars, which I also find to be a very tidy way to store the phone