Existing iOS version of the app works off Apple Maps, Google Maps OpenStreetMap, which gives pretty good coverage.
Apple Maps allow creating routes in a large, but yet limited number of countries (see the full list of countries supported by Apple Maps here: apple.com/ios/feature-availability/#maps-directions
OpenStreetMap and Google Maps offer better coverage and work virtually everywhere.
If you keep getting "Invalid route" error when using the app, please try switching the maps in the app settings.
In the android version of the app Google and Openstreetmaps are available.