Occassionally I fly missions in Pix4d and upload to DroneDeploy for processing. Pix4D offers a double-grid for supposedly better 3D calculations. For those who will say, 'just plan a second mission in DD with the flight turned 90º', I know, I know...
I'm not looking to open a large debate over this, I just thought y'all would find my flight path as amusing as I did! (see pic).
The squiggles in the middle/left square is where I took off (then hovered for a bit), then it pulled some donuts on the east end at 90m AGL, before finally attempting to stay on the mission lines. I haven't received the map yet, so fingers crossed!
And now in the App Market, I just noticed DD has 'AutoFlightModes' which offers the cross-hatch flight pattern. Pix4D is history to me!