I have used this App for over 8 months, and is by far, the best golf GPS for the money. I had a sky caddie before, and it was not half as good as this app. Don't waste your money on any of the annual dues GPS units, buy this app and have everything you need. 

I have the iPhone 4, and only uses about half the battery during a 4 1/2 to 5 1/2 hour round. Turn off your Wi-fi if it is using more battery life than that. 

Anyway, must have for all serious golfers.