For the first time in six years, Sun Country will have an app for its travelers.

The app is still in development and won't launch until later this year or early 2024, a spokeswoman for the carrier said. But the creation of one shows the budget-friendly carrier is willing to join the ranks of other airlines that have invested in technology to better engage and serve their passengers.

What features the app will have are not yet known. Company officials reportedly made the announcement at this week's Aviation Festival in Miami, according to industry publication the Airline Observer.

Other budget airlines like Spirit and Frontier have had apps on the market for several years, said Kyle Potter of Thrifty Traveler, a Minnesota-based travel and flight deal website. Major carriers also have apps, and it's not unusual to see people boarding planes using the boarding pass within an app instead of a physical printed ticket.

Having an app has become the bare minimum, Potter said, and this could simply be a matter of Sun Country playing catch-up.

"I think a lot of Sun Country customers have been pretty shocked after booking a flight with the airline and going to the Apple App store or the Google Play store and looking for the Sun Country app to find absolutely nothing," Potter said.

Whatever it contains, it must meet the high-tech demands of today's travelers, or the airline will hear their complaints, experts said.

"What travelers want with a mobile app is a gateway to the complete airline experience," said Henry Harteveldt, president and a travel industry analyst of San Francisco-based Atmosphere Research Group. "That means booking flights and managing your flights, and importantly within that, the ability to rebook your flights when or if your original flight is delayed or canceled."

Harteveldt said those features can also free up some of the airlines' customer service options, since passengers won't have to tie up phone lines, queue at reservation desks or flood the website in order to switch their travel plans.

Harteveldt added any airline app should "start and end with booking and travel management."

"If that's all Sun Country is doing, then that is a big win," he said.

Sun Country's revenue has grown 72% since 2017, when Apollo Group Management acquired it in 2017 — also the most recent time the company had an app — going from $559 million to $962 million through the past 12 months ending in the first quarter of 2023. The company went public in 2021.

Speaking at the 30th annual Transportation, Airlines and Industrials Conference on Thursday, Sun Country President and Chief Financial Officer Dave Davis said the company is projecting low double-digit growth this year.

Besides painless booking features, there are a few other features Sun Country might want to consider, Harteveldt said.

Travelers also want to prepay to check bags, or indicate how many bags they plan to check when they check-in for the flight. They also want a system for tracking those bags through the travel. Passengers also want the ability to choose their seats and pay for them if there is a fee as well as pay for priority screening or priority boarding if the airline offers that.

In Europe and Asia, airlines have extended apps to include the on-board experience, letting passengers prepay for and preorder meals, beverages and snacks. That helps the airlines better manage inventory of items they need on each flight, Harteveldt said.

The Delta app, for example, also tracks progress for its SkyMiles loyalty program.

"There are airlines that are beginning to realize that their mobile apps can be gateways to much stronger, much more robust and much more financially rewarding customer relationships," Harteveldt said.