There is a whole armada of travel apps out there. Not being much of an app person, I can’t claim to have tried that many. But one that has become an essential feature of my mobile devices is TripIt.
Even in its basic (read ‘free’) format, Tripit is a sanity saver. Its easy to set up and access automatic organization of travel itineraries and essential relevant information has helped me on too many occasions to mention. It works well in Android and iOS and even a grumpy old technophobe could figure out how to use it. Oh, and did I mention that the basic version is free?
I understand the Pro version ($49 US a year, I believe) has some impressive features, but I’ve done just fine without them. Highly recommended for any traveler.