Sometimes innovation comes from unexpected places. Personally, I wouldn't have thought Expedia would turn out to be one of the most well-designed, innovative, and fun apps I've tried on iOS lately. But it is. Released two weeks ago, Expedia 2.0 is a universal app developed by Mobiata, and it is an example of how a hotel-booking application should scale elegantly across different displays without providing a confusing and frustrating experience (a common thread of hotel-booking apps and software).
On the iPhone, the app starts with a gorgeous mosaic of deals for hotel rooms and flights. Photos are nice and compatible with the Retina display, and even the loading indicator has been designed with a hotel theme in mind: for flight search, the same indicator changes to another design, but I won't spoil it here. Once you tap on a hotel, information is laid out elegantly with swipable galleries, green-colored icons for services offered by the hotel (WiFi, parking, etc), price tags, and an embedded Maps view. You can check out reviews, change the number of people requesting a room, and tweak the duration of your stay with a custom date picker that allows you to select multiple days with a single swipe. On the iPad, the same information is conveyed with a "stacked panel" UI that lets you switch at any time between map view and hotel information.
For flight search, the app is possibly even more pleasant to use. With blurred backgrounds and an Apple Store-like menu that progressively collapses as you confirm your choices, Mobiata managed to make the purchasing experience incredibly natural and good-looking in spite of the amount of data they need to present to the user.
The Expedia app is full of nice touches and details. Even if you're not interested in hotel or flight booking, you should check it out for its design choices and interaction patterns. Free on the App Store.