Is there an iPhone app that tells you which songs you listen to the most?

I would really like to know what the top tracks on my iPhone/iPod are, and how many times I've listened to a song. Is there an app for this?

You can just look at your play count on iTunes. There's also this program called Last.fm that takes the tracks you listened to and keeps track of them on a website.

No app, its built in the Music app.
Music > Playlists > Top 25 most played