The iTrip app is a tool to schedule your trip. Once you set the starting location and your final destination, iTrip will compute all possible routes to arrive there. You can also set a preferred departure or arriving date/time. You can view each route on a map, and you can then get direction on an Apple map. Finally, you can save a trip for future reference.
Please, note that the traffic is unpredictable. There can be a traffic jam for many different reasons. Because of that, iTrip can not accurately predict the departure time