There is a small country in Africa with only two controlled airports. A friend from there is now with me and while flying with me discovered Skydemon. He owns three aircraft over there, on of them a SET. Obviously nobody from there is going to subscribe since there is no coverage and Skydemon is not going to code since there are no subscriptions from over there. What would it take to get the ball rolling?

You can always create your own custom data (airspace, airfields etc) with the included Data Creator app that ships with SkyDemon Plan.

Tim,

I have now coded most airfields, navigation aids and CTRs for this country (Cameroon). I am having some trouble with the coding of the TMAs because their shape is a bit irregular and I don't understand how the tool works by drawing from a map. For some parts of the TMA I have to follow the FIR boundary. I have Wacom tablets for easy drawing.
Is there any chance of making the VFR approach charts overlaid on the general geographic map? 
Are there any open source roads/rivers/city maps available? 
Also, for the smaller airfields I only have the ARP and the runway alignment, not the coordinates of the runway ends. How can I show a runway alignment without coordinates?

Sorry, we can't really offer support for custom data creation. It's hard, and a huge topic, and we have dedicated members of staff to do it in the countries we DO cover.
We couldn't integrate georeferenced plates for a country we don't even supply charting for.
I don't know about availability of geographical data in that region.
A runway should be shown on the airfield icon even if threshold coordinates are not available, it will just not be precisely mapped when you zoom in.

Runway threshold coordinates: have you tried to get them from Google Earth?

State border: you can copy - paste the coordinates from enclosed kml-file.
(from http://www.diva-gis.org/gdata)
I an not sure it is up to date. And generally FIR boundaries are a little bit different due to polygon simplification.

Joseph,

The state borders are already shown in the desktop Skydemon version together with terrain and maximum elevation numbers. 
I need to get the custom aeronautical data in place in the tablet, see my other post.

DirDej,

You wrote had created custom data.
Are your custom data visible in PC (SD main window) but not visible on tablets?
Have you copied corresponding custom files from PC to your tablet?

Joseph,

My custom data (airports, TMA, intersections, reporting points) are visible in PC and tablet (after load from cloud);
On the PC I can see the basemap for Cameroun with boundaries and terrain. On the tablet I see no basemap at all, just maximum elevations and terrain in the vertical radar window, not in the plan view.

DirDej,

The missing terrain seems the most serious trouble. SD team could help maybe.
I would continue with airspace file with WGS coordinates from cameroon_stateborder.kml (notepad). Then put important towns into waypoints file - also with a text editor.

PS:
Obviously there are better tools then notepad and copy-paste. (The source kml has around 30,000 points...) Find enclosed the airspace file (accuracy 500 m, 995 points in total - due to tablets) created from kml sent to you recently: The cost line is manually edited, the point density reduced by GIS software.