We've tried that app - it works very very well - within 1 or 2 knots of the $149 Kaindl Windtronic Wind meters...
It might work in queensland but useless in WA.... the dial only goes up to 25 knots.
Oh how I miss WA wind... 
Well if its over 25 you know you're getting your 7 out anyway :P
I bought the app and tried it last summer, worked a treat.. didn't expect it to be so accurate
Here's a free wind meter ... it requires the use of two highly accurate visual observation devices mounted either side of your nose ... calibration can take a few sessions, though...
www.seabreeze.com.au/Members/Help/Beaufort.aspx
yea same here, we were up at eliot heads and there were 41 knt gusts comming though really gusty squally ****, the iphone app only read 25 knts and someone elses windmeter (which was a proper one) was reading 41
