May be this is interesting for someone:
The autopilot in my plane is connected to a Garmin 296. Since the SD Android does not support the route export to a Garmin (SD for PC is able to do that) I faced the problem how to get the route (with SD planned route) to my Garmin to control the AP?
There is a little nice app called “Garmin Exchanger” on the market. With SD Android you plan your route and save it as a GPX file. Then you connect the Garmin via USB to the tablet and send the route.gpx with Garmin Exchanger to the Garmin GPS. That is all.
It is important that you have an android device with USB host mode (like NEXUS 7 2013).
I think this app will also work with the other aeronautical Garmins (like 396, 496, …).
There are two little things you have to consider:
1. If you set a waypoint with SD on a position with no geographical location than the gpx file contains no name for that point and during the export the app will cancel the transfer at that point. So you have to give these unnamed points a name before export. You can do that with “edit” in that app.
2. The difference between the SD PC route export and this Garmin Exchanger export is: All exported waypoints in the Garmin get the geographical names instead of the ICAO designators (if the waypoint is set on an aeronautical position like airfield, rep point etc.).
Good luck!