private static void navigateCache(final Activity activity, final Geocache cache, @Nullable final App app) {
        if (app instanceof CacheNavigationApp) {
            final CacheNavigationApp cacheApp = (CacheNavigationApp) app;
            if (cache.getCoords() != null) {
                cacheApp.navigate(activity, cache);
            }
        }
    }
Handles menu selections for menu entries created with
{@link #showNavigationMenu(Activity, Geocache, Waypoint, Geopoint)}.
main/src/main/java/cgeo/geocaching/apps/navi/NavigationAppFactory.java