We (Friends of The Web, a development company) were wondering the same thing, so we built our own! I can't link to it (not enough reputation in the forum), but if you search for Barometer++ in the App Store, you'll find it (it's about 5th in search results right now).
It shows you the raw measurements from your new iPhone's barometer, and additionally shows you recent changes in elevation. The app can also optionally post high and low scores to Game Center, to compare with other users! We think it's a great little app!
10-01-2014 04:07 PM