I noticed (mainly in other forums) that there seems to be some confusion when it comes to selecting the right (oof-road) navigation programs.
User install a program they downloaded only to notice it is basically of no real use to them, so I try to clear some things up here:

1. Before deciding on any off road GPS program you should check if it supports maps of your area!
The best way of doing this is by checking the download offer first for the available map sources and how to use them, if not enough info is available, please check the programs play store link or homepage for further infos!
2. Make sure that you either use a program that supports offline maps or that you have proper cell phone coverage in the areas you need - best option is to have the maps stored on the device instead of using offline solutions.
3. If you need a GPS solution for very remote and badly supported areas, like certain parts of Africa, Asia or south America, it is often best to check the Garmin homepage for available maps and to use a dedicated Garmin device - even if it means you have to buy maps and a GPS (please consider sharing new maps though).
4. Be aware that track and road coverage of a map often depend on availabel data, this means maps from OPSM project can often be better than official solutions.
Another thing to consider is that some countries offer official mapping data free of charge. In most cases these maps can be converted using the available tools for the program of your choice, if they can't be used directly.
5. Most off road solutions only offer a moving map, that means you see where you are on the map while it moves along but you won't get any spkoen directions! You have to check the map and find your own way in most cases.
To my knowledge only Garmin offers spoken directions even when using their topo maps.

Having said that, I also must point out that converting maps (if not DRM protected) is pretty straight forward.
So if you need a solution for an area that seems to be totally unmapped in digital form, you can still opt for programs like Ozi Explorer and scan paper maps for the use on your GPS.
I know I can not cover all possible aspects and problems, so if you have any questions not answered elsewhere, feel free to ask them in this thread and me and the team will give our best to make the impossible possible for our users.