As @PingSpike and @milkmanchris have said Litchi is the way to go. It’s not perfect but has always worked well for me including RTH . For general flying it is very similar in use to DJI Go4, for waypoint use it’s in a class of its own.
If you have a tablet or desktop then using mission planner is a joy. Not only can you plan missions you can fly them on screen using Google Earth in 3D. (export the *.kml file as a Litchi Virtual Mission) . This will both check your flight path for obstacles or unintended deviations and will show you the camera view throughout so that when the weather allows and you make the flight there are no unpleasant surprises. And if oyu go back to repeat the flight days or weeks later you aircraft will follow the same path.
It’s seemingly expensive for an app, especially as so many are free (apart from ads and in-app purchases!) but it is worth the money. Look on it as an accessory for your aircraft - you’d spend the same money on an ND filter or a decent skin.