[iPhone God App] It was found using the Altimeter actually

Altimeter puts the GPS capabilities of your iPhone to use as a handy altimeter. See your current altitude, set the base altitude before you begin a climb, run, hike, or bike ride, and then check again at the peak to see how far you have climbed. You don't have to have your iPhone on all the time, just turn it on whenever you want to check your progress. Altimeter remembers your starting altitude even when your phone is off.

NEW*** Greatly improved GPS tracking, accuracy, status reporting.

NEW*** Now calculates your climb rate in ft/min or m/min.

This version now also keeps track of your starting and ending time, and shows the elapsed time as well as the change in elevation. Great for comparing your times to complete your favorite hike!

A great tool, but of course it's only as accurate as the GPS readings that you are getting. It works best with clear views of the open sky, and won't work on devices that don't have full GPS hardware, like the iPod iTouch. Altimeter uses the iPhone GPS hardware fully, but often you may need a little patience while the hardware acquires the satellite signal. As with other iPhone GPS apps, it usually takes between 30 seconds and a minute to get a ‘lock’ on a satellite if you are in an area with a direct line to the sky (away from tall buildings and trees for best results).

Altimeter runs even better on iPhone 4!

Note that the little gear activity indicator does not run all the time, it only turns when a new altitude reading is received.

The civilian GPS system limits accuracy to about 50 feet, and does not provide altitude readings above 50,000 feet, but in our field tests we find that even small changes in actual elevation are reflected in the received data. So, as you ride or walk up and down hills, with good atmospheric conditions, you will get good information about your change in altitude.

NOTE: Only the iPhone 3G, 3GS, and 4G have actual GPS hardware, so those are the only devices that Altimeter will work on. It will not work on an iPod Touch. However, even if you have no cell phone service Altimeter will still work, as long as the device has a clear view of the GPS satellites.