Several mentions in this thread of WeatherFlow products (WindAlert, SailFlow), another local favorite is iWindsurf. As I mentioned above, they are related, and definitely have the similar look/feel, if not identical forecasts.

More info: http://www.weatherflow.com/consumer-products/

Makes me wonder how independent the others are?

In any case, no forecast or tool is 100% correct all of the time, and sometimes they are WAY off. The very best (usually paid) include a confidence level, and other things that might happen on a difficult day.

Mike