One of the ongoing problems travel search sites have found when developing their mobile apps is that they are at the mercy of their product suppliers.
In short: consumers may have a fantastic user experience when searching for flights, hotels, etc, on a mobile application, but metasearch brands have to send the user off to the supplier or intermediary website to complete the booking.
And herein lies the danger, as many suppliers are, well, not exactly optimised for mobile or, if they are, sometimes provide a bit of a jarring switch for the user after heading off from the referring site.
In a quiet release a few weeks back (it had the small matter of its IPO to handle), Kayak introduced a new feature to its iPhone application to allow third party sites to be contained within the existing app.
Users, when selecting the "book" button from search results, now find themselves at the booking window of the third party but still within the Kayak app.
The hosting of mobile websites within applications is a standard feature of the iOS application functionality - it just hasn't been used extensively in travel apps.
Every third party site that Kayak works within is included in the feature, chief architect Bill O'Donnell says.

"We always look at ways to make the booking process easier – it’s part of our ongoing focus to deliver a comprehensive, intuitive travel planning experience.
"If someone leaves the app to book hotel or flight reservations and they want to come back, they have to go find the KAYAK app again on their phone. This update completely eliminates that step. It also allows us to enable the autofill feature [another new tool which populates name and billing info if the user saves their details]."
The latest update coincides with a booking service within Kayak (not the intermediary or suppliers sites) for car hire products. Initially only available for US car partners, O'Donnell says the feature will be rolled out to other territories shortly.
The handling of bookings is something Kayak has played with for well over two years on the main website, including a deal with Travelocity for hotels.
But with the all-in-one-place approach for its mobile apps, Kayak - originally just a metasearch engine for product - is once again showing that, at least in the eyes of the user (who often doesn't care or notice) it is becoming far closer to the OTA model in terms of user experience.