I have used both the Mac OS and IOS app versions of this excellent, versatile routing software for racing offshore in the NE USA over the last 6 years. It integrates seamlessly with the NKE equipment on the boat and my Iridium Go for satellite based downloads of grib files. It is intuitive to use and has an astonishing array of features from boat polars to being able to overlay charts with wind and tidal current data as well as having full AIS compatibility. Not only does it work out routings for you but is also a very effective chartplotter for a fraction of the price of dedicated marine equipment. During the off season I use it in virtual mode for on line sailing racing to try and sharpen my navigation skills and strategic decision making. On top of all this the developer is continually refining and adding new features and has always been very quick to respond to any questions I have had. Highly recommend it.