I use APM Planner 2 on a Raspberry Pi 3 connected to Solo from my backpack ground station.
More info about APM Planner 2 can be found here:
APM Planner 2 Home — APM Planner 2 documentation
To download APM Planner 2, you can head over here:
APM Planner 2.0
This is a quick video I made to show...