You’re always best served by having a standalone flight tracking app that’s easy to access and will update often and quickly—that way, you can tap into your flight information as quickly as possible when you’re in a rush. The best of the bunch is FlightTrack. It follows domestic and international flights, telling you not only the scheduled departure and arrival times, but also when the plane actually leaves the departure gate and when it will actually arrive. A map tracking the plane's altitude and location is a geeky but nice feature. The standard version costs $4.99, but the $9.99 Pro edition will integrate with your TripIt itinerary.