Mobile app indexing could be one of the quieter trends to emerge in travel marketing during 2016.
HotelTonight and Chimani, a provider of tourist apps for National Parks in the US, are part of a pilot scheme from Google to allow content containted within apps to be found in traditional search.
The search giant's App Indexing project makes it possible for information usually contained within the walls of a mobile app to be released into search engine result pages (SERPS), even if there is no existing web content available from the same provider.
The New York Subway, Weather and Daily Horoscope are three of the other seven brands that have been working with Google in recent months to test the technology.
For example, at Chimani, Google has indexed 25,000 points of interest and events in National Parks and other outdoor destinations that are usually held on the company's suite of apps.
The project is now slowly being rolled out to other app providers, including hosts on iOS-enabled devices.
Google shows an install button in SERPS so that those who find content can then download the app to their mobile device.
If a user does not want to install the app just yet - if they are on a laptop, for example - they can stream the content instead on a web page.
Google has been indexing app content (with a web-based match) for a number of years, but the latest phase is exclusively around giving app-only brands the opportunity to be found in SERPS.
From Google's perspective the project goes some way to ensuring it doesn't become a bit-part player in the gradual creep to mobile-only behaviour by device users.
For the likes of HotelTonight et al, Google has allowed them to retain a presence back in the old world of desktop search, despite being solely app-based businesses.