They’re not checking Facebook (FB), watching the latest viral animal video on YouTube (GOOG) or tweeting about the antics of the misbehaved passenger in row 12.

More likely, they’re using their airline-issued devices to determine which passengers will have tight connections, who’s having a birthday, and who’s entitled to a complimentary drink.

In the same way mobile technology has literally lightened the loads of pilots by replacing stacks of paper charts and manuals with programmed iPads, apps on mobile devices that can facilitate sales and access passenger information are changing the way flight attendants work in and out of the cabin—and they’re helping airlines improve their bottom lines.

“Equipping crew members with digital devices gives them access to information that allows them to address passengers in a relevant way,” says Raymond Kollau, founder of airlinetrends.com. “It’s also a way to increase inflight revenues, as the transaction process is quicker.”

In late 2012, American Airlines (AAL) became the first airline to equip all its flight attendants—at that time more than 20,000—with mobile tablets for use on board its planes.

Now American has about 26,000 flight attendants (as a result of its merger with US Airways), and all are equipped with Samsung Galaxy Note 3 phablets. That enables them to receive corporate email, check in for their shifts, and get real-time access to passenger seat assignments, loyalty program status, special service needs, premium class food and drink choices, connecting gate details and other information, says Charles Sucur, American’s senior manager of onboard products and flight service technology.

“We also provide third-party apps that help them serve customers better, such as Google language translator, FlightAware and weather,” says Sucur.

An electronic version of the 2.5-pound paper manual flight attendants previously carried also is loaded onto the devices. “It was a big, square, hulking thing they used to put in their carry-ons that took up a lot of space,” says Linda Carlson, American’s director of flight service communication and technology.

Now, says Kollau, about two dozen airlines around the world, including Delta (DAL), United, JetBlue (JBLU), British Airways, KLM, Air France, Lufthansa, Iberia, Emirates, Etihad and Qantas, have joined American and other carriers in equipping cabin crew with smartphones, tablets and phablets. Delta Air Lines’ 22,000 flight attendants have been using smartphones in the cabin since 2013.

“In the past, we relied on a lot of paper,” says Edelyne Remy, a flight attendant-qualified program manager with Delta’s onboard services division. “Now we can give real-time feedback to the company on things such as catering discrepancies and missing items on the aircraft. And with our guest services app, we have more information about customers and can interact with them better.”

Approximately 3,700 Alaska Airlines (ALK) flight attendants have been using mobile apps loaded onto iPhone 6 Plus phones since May 2015.

“It’s changed our jobs in so many ways,” says Renee Goldfoos, who has been an Alaska Airlines flight attendant for 31 years.

In addition to transforming the bidding process and check-in procedures for cabin crew members, Goldfoos says apps on their carrier-issued mobile devices now allow flight attendants to access information such as the seat locations of unaccompanied minors and the location of elite mileage members entitled to special perks.

“Before, all of these things were just on one piece of paper that we’d all have to share, and it was kind of hit or miss whether the printer at the gate had good ink that day or whether a drink got spilled on the paper once we had it in the cabin,” says Goldfoos. “Now each of us has all the information on our apps.”

This summer, United Airlines issued iPhone 6 Plus smartphones to more than 20,000 flight attendants. Stephanie Lex, a flight attendant with the airline, now uses United’s customer service app to resolve problems such as when two people show up with boarding passes for the same seat. “Before, I’d have to call the gate agents and wait for them to come down the ramp with a paper seat assignment chart while people stood around being stressed in the aisle,” says Lex. “Now I can use the app to resolve the problem instead of just passing the buck.”

Going forward, flight attendants and other airline personal, passengers and third-party developers are exploring additional ways in which the in-cabin devices can be utilized.

The wish list at Alaska Airlines is more than 40 items long, says Shelly Parker, director of Inflight, and includes using the digital devices to list the names of qualified people on a flight who could help out in the event of a medical emergency. Another suggested use is having an in-app form that indicates whether an unaccompanied minor or a passenger with a special need has been given a required briefing.

SITA Lab, which researches air transport technology, is looking at how wearable devices, such as Google Glass and Apple watch (AAPL), might be integrated with CrewTablet, the SITA OnAir system cabin crew members are using or testing on more than a half-dozen airlines.

Increasing passenger-crew interaction by integrating CrewTablet with the in-flight entertainment systems on airplanes and personalizing the experience more also is on the agenda. “For instance,” says SITAONAIR Portfolio Director Toby Tucker, “the airline might be able to send a happy birthday message to an individual’s seatback screen.”

Whatever the end use, the digital age has reached the sky, and there seems to be no limit to its end uses.

Harriet Baskas writes the “At the Airport” column for USA TODAY and is the creator of StuckatTheAirport.com.

This Executive Travel story appeared in the September 15, 2015 issue of Fortune.