Hotel guests can also use the Kayak app to pick a type of room or to request housekeeping or a late checkout.

Giant hotel operators such as

Hilton Worldwide Holdings Inc.

and

Marriott International Inc.

already offer apps that allow their guests to do things like open their room doors or order a room-service cheeseburger at properties across the U.S. and abroad.

But independent hotel owners don’t have the financial resources to invest in systems that offer these features. The Kayak app would elevate this service to the same level as the biggest brands, said Kayak Chief Executive

Steve Hafner.

“Millions of consumers already have the Kayak app on their phones,” he said. “We see a big opportunity to apply our audience and technology to the accommodation space.”

Kayak is scouting other properties, from Los Angeles to Berlin, for future hotel sites, Mr. Hafner added. The company, which is part of online travel giant Booking Holdings Inc., is also exploring a Boston-area location to offer short-term rental accommodations.

The travel search company’s foray into the hotel-operations business is the latest sign of how companies connected to the hospitality industry are invading each other’s turf.

Airbnb Inc.

lists hotels on its site, and in 2019 acquired the hotel-booking app HotelTonight. Marriott, meanwhile, has entered the shorter-term rental business. The big lodging brands have been trying to wean customers off online travel agents, such as Booking and

Expedia Group Inc.,

by incentivizing guests to book directly through their apps or websites and offering lowest-price guarantees.

Kayak, in offering hotels a phone app that allows guests to interact with the property electronically, is providing a service that has been in greater demand among those traveling during the pandemic.

But it is also well behind some of the global brands that have offered this amenity for years. Hilton, which started offering a mobile phone room-key option in 2015, said that guests have opened hotel doors more than 111 million times with this digital service.

Kayak was founded in 2004 by Mr. Hafner and a partner as a so-called metasearch site that enables users to compare prices for hotels, airlines and other travel services from a variety of online travel agencies. Before the pandemic, Kayak processed around six billion travel requests a year, Mr. Hafner said.

Rami Zeidan,

CEO of Life House, founded the company in 2017. His firm operates more than 20 properties, and it created proprietary software that helps owners run their hotel back-office operations and determine room pricing to help maximize revenue.

The Kayak Miami Beach had been run as a Life House branded hotel until it closed about a year ago at the start of Covid-19 shutdowns. It will be reopening for the first time in April under the new Kayak brand and will start taking reservations on Tuesday.

Write to Craig Karmin at craig.karmin@wsj.com