Here is a screenshot from (https://www.windfinder.com/#14/-43.5493/172.7125) and your app for the same location, as you can see your read is over forty knots from the wrong direction.
 

I've been using your app lately (looks great) but i'm regularly getting weird wind information regarding both direction and speed! At the moment apparently the wind is blowing @ 76kt's when its probably around 25kts - any answers?