I agree it could use a clearer user guide, but I was able to figure it out:Select a "journey". With that journey selected, one can now add "routes". Select waypoints by searching, or directly touching the map (useful when zoomed in pretty far).
One typically needs to resort the order of the waypoints, since you probably are adding intermediate points. Click on the "Edit" label, then touch the waypoint you want to move on its far right edge, then drag. If you want to do a similar route but leave out some destinations, create a new blank route, select the route with excess waypoints. Click one you want to include. A "copy to route" appears. Select it, and it will give you a list other routes you can copy it to - select your new blank route.
It does crash a little too often, but its workable. You can get a directions list, but it doesnt show miles from the last waypoint - that would be a useful update to the app for multiple day trips.
Robert Wilson about Routes. Planning your journeys