Android smartphone and tablet owners turning to apps to book or research travel most often turn to TripAdvisor, according to an exclusive monthly app index provided to Mobile Strategies 360 by digital analytics firm SimilarWeb. The index reveals the Top 10 apps each month in a range of verticals based on the app’s number of current installs and daily active users.

In addition to ranking the Top 10 apps, the index also looks at two other telling metrics within each of the Top 10 apps: app retention, or the percentage of users with an app installed who opened the app at least once within 30 days after installing it; and the percentage of each brand’s total web traffic that goes to its mobile site.

For February, TripAdvisor by far had the most downloads among U.S. Android devices. 16.64% of those surveyed had the TripAdvisor app. That was far and away a higher percentage than No. 2, Southwest Airlines, with 1.60% of U.S. Android devices having the airline’s app.

When it comes to app retention, Marriott International ranked first with 3.42%, followed by Foursquare with 2.83% and TripAdvisor with 2.11%.

Five of the Top 10 Android travel app brands also get more traffic from the mobile web than from desktop. Those include: Foursquare (53.19%); TripAdvisor (52.18%); Marriott International (52.17%); Hotels.com (51.82%); and Expedia (51.58%).

“The battle among travel apps is fierce,” says Pavel Tuchinsky, digital insights manager for SimilarWeb.  Hotels, online travel agents and airlines are in a race to secure bookings for flights, rooms and accommodations, he says. That’s illustrated by even the most used travel app, Marriott International, being opened by just 3.42% of users in the 30 days after the app was installed, he notes.

As for the overall app winner, TripAdvisor, Tuchinsky says added capabilities to that app are helping drive app downloads and use. “The brand has evolved from its origins as a review site for destinations and hotels, to a one-stop shop for every aspect of a vacation [including booking],” he says. “TripAdvisor’s Instant Booking Platform grew steadily since its rollout in 2014 and Priceline’s Booking.com was recently added to its roster of participants.”

When it comes to booking hotels alone, Tuchinsky says the Hotels.com app, which ranks No. 4, drives loyalty with its extras like secret prices only for its registered users. The app is also enhanced with reviews from Hotels.com users and from TripAdvisor.

The only hotel brand on the list, seventh place Marriott, boasts rich app features such as Mobile Request and an “Anything Else?” option, Tuchinsky says. The Mobile Request feature allows users to make requests as many as 72 hours prior to their stay and includes such options as asking for additional pillows or checking in via a mobile device. The “Anything Else?” tool in the app allows guests to chat with Marriott’s staff about everything from restaurant reservations and airport transportation, to setting up a surprise welcome gift for a traveling partner.

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