It's free, has satellite view, you can mark the courses yourself (takes only about 10 minutes) using your computer, keeps track of all your stats, has "ACTIVE SHOT" feature to see how far you hit a club.
Only uses about 20% (often less) of your iPhone 4 battery per round. You need iOS 4, which you probably do. All those negative comments in the app store, I think, are due to not having iOS 4.
Trust me. For free, you cannot go wrong with this program. It is great!
I don't like inaccurate yardages even if its free. The iOS 4 doesn't magically make the aGPS accurate, that's probably why the negative comments are there.