The Trip app is a tool to schedule your trip. Once you set the starting location and your final destination, the Trip will compute all possible routes to arrive there.
It is possible to add intermediate stops
You can also set a preferred departure or arriving date/time. Wouldnt it be nice to know when to departure so that you arrive at a given time? Because the traffic is unpredictable, it can not accurately predict the departure time!
You can view each route on a map, and you can then get direction on an Apple map. Finally, you can save each trip for future reference.