Once you'd downloaded a map, it will do everything offline that it can do online.
With Onx, the biggest deficiency I've found is that it won't store offline maps on the SD card. I'm limited for space so I sometimes have to delete some maps to make room for a new one. My SD card has room for the whole state but Onx can't access it.
Can't figure why you'd want to store offline maps on an SD card when OnX keeps them for you. If you don't need it for that hunt, dump it from your phone and pick it back up when you do need it. I've hunted Alaska and Arizona without coming close to using up storage space.
