The SailTimer app is free. You can import the excellent Navionics charts with in-app purchase. Display your optimal route through multiple waypoints.

Compare 3 different types of marine weather animations: crowdsourced wind maps with NOAA GRIB (US model), AI forecasts (European model), and Weathernews Inc. (WNI) marine weather for ships (Japanese model). When they are all consistent, you know your routing is based on accurate information. Each has a low-cost in-app subscription and 7-day free trial.