[GPSNavX]

With 3.0.1 you will need to go to the "Routes" tab, select the Route you want to edit, then tap the "+" button, then the "+" button next to the waypoint you want to insert after. Select "Done", then select "Select Waypoint" and choose the waypoint you want to insert.

With 3.0.2 I have significantly reduced the number of steps needed to add/insert waypoints to the route.