Export folder of waypoints etc to GPX

I use GaiaGPS on android offline for SAR. One feature we'd love is the ability to export a whole folder of waypoints to a GPX/KML file as opposed to having to do each waypoint individually. This would allow us to share assignments and routes while in the backcountry. The website has this ability but the android version doesn't. Of course, offline in the backcountry, we can't use the web version. Ideally we'd be able to save it to an SD card/USB memory.