Check out this new app. You put in your starting point and your ending point and it plots the route for you, taking into account wind and currents. It's in beta testing and they are looking for input. There are some known bugs. Mobile apps for android and iOS are already in development.

https://app.savvy-navvy.com/chart/@40.2982006,-15.2897657,4.91z
edited by DariaBlackwell on 1/9/2018

Vice Commodore, OCC 

Now here is a confession that I’m almost too nervous to share with Dick! I have used such a tool for planning purposes and found it really good for the reasons Daria states. Both the Navionics Boating App and the PredictWind App have similar automatic routing functionality built in. They offer very quick (and mostly accurate) routing through complex territory and can save a lot of laborious work. Absolutely not to be relied on for real world navigation but well worth investigating for those prepared to treat it as an aid rather than as gospel. The Navionics version can be configured to mitigate risk as, I suspect, most others can. They certainly have very obvious cautionary notices that leave the user in no doubt where the navigator’s responsibility resides.

So once again my technophilia has been outed and I nervously await the response!
Simon