A few notes here:
1) The USA does not have roads/rivers/cities either right now, just like it says a few posts above. We don't have a great source for data anywhere yet. We're working on it.
2) The data PockeFMS has are per-compiled images. This means they are huge, and pixelated at high zoom levels. It also means you can't declutter things, it's all or nothing. Additionally, they buy these from another source, so they would cost significantly more if we wanted to include them.
As you can see below, this is an image from PocketFMS near Seattle, with an image that is 3NM wide, and the resolution is not great.
Remember that internet connected devices don't have size restrictions. They can pre-compile images and it doesn't matter if a whole country takes up 50,000 gigabytes of data and would take months to download, because you only ever look at a small area at once.
3) It's not possible for us to release the map format because it doesn't exist. Until the software understands what a road is, there's no way for a database to show a road. Our system doesn't store images, it stores things like "an airspace of class C from lat/long A to lat/long B." So until it knows what an airspace is (or a road, river, or city) it can't draw it.
Overall, basemap details are a high priority for Dynon, and we're looking into it, but we need to find a good, solid source of data for the whole world that is affordable, and then get this folded into the software, so we can't offer any promises when this will be available.