Apple CEO Tim Cook discusses the new iPhones at the Steve Jobs Theater during an event to announce new products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

Apple unveiled three new iPhones on Wednesday, including its biggest and most expensive model yet, as the company seeks to widen the product's appeal amid slowing sales.

CEO Tim Cook showed off the iPhone XS Max, which has a bigger screen than the one on last year's dramatically designed model , the iPhone X. It'll cost about $1,100, topping the iPhone X, which at $1,000 seemed jaw-dropping at the time. An updated iPhone X, now called the XS, stays at $1,000.

As with the iPhone X, both new phones have screens that run from edge to edge, an effort to maximize the display without making the phone too awkward to hold. The screen needs no backlight, so black would appear as truly black rather than simply dark. The Max model looks to be about the size of the iPhone 8 Plus, though the screen size is much larger.

The iPhone XS Max, which will be available on Sept. 21—with orders open the week before—represents Apple's attempt to feed consumers' appetite for increasingly larger screens as they rely on smartphones to watch and record video and to take photos wherever they are.

By making more expensive iPhones, Apple has been able to boost its profits despite waning demand as people upgrade phones less frequently. IPhones fetched an average price of $724 during the April-June period, a nearly 20 percent increase from a year earlier.

Phil Schiller, Apple's senior vice president of worldwide marketing, speaks about the Apple iPhone XS at the Steve Jobs Theater during an event to announce new Apple products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

Apple also showed off a cheaper iPhone, called the iPhone XR. It has a traditional, lower-quality screen and an aluminum body; it's physically smaller than the iPhone 8 Plus but has a bigger screen. It'll cost roughly $750 and come out on Oct. 26.

All three new models join the iPhone X in getting rid of the home button to make room for more screen. They will have facial-recognition technology to unlock the device.

Although it didn't sell quite as analysts anticipated, the iPhone X still emerged as the most popular in Apple's line-up, according to Cook. That emboldened the company to aim an even more expensive device at the affluent households that tend to gravitate to its products, especially in the U.S. and Europe.

Jonathan Ive, Apple's chief design officer, left, looks at some new iPhone models with CEO Tim Cook during an event to announce new products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

For everyone else, many of whom are still using iPhones they purchased several years ago, there's the XR.

"I am going to go out on a limb and say the XR is going to become Apple's top-selling iPhone," said analyst Patrick Moorhead of Moor Insights. "It is a smart strategy to keep more people in the Apple ecosystem and get even more people to come into it."

The next major update to the iOS will be released next Tuesday, followed a week later by a Mac software update. Both will be free to install.

Apple CEO Tim Cook, left and soccer player Alex Morgan discuss the new Apple Watch 4 at the Steve Jobs Theater during an event to announce new products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

Apple also announced updates that push its Apple Watch further into medical device territory. It has a larger screen and a built-in heart sensor that the company said can detect irregular heart rates and perform an electrocardiogram. The latter feature has been cleared by the U.S. Food and Drug Administration, the company said.

Ben Wood of CCS Insight said getting U.S. regulatory clearance for that is a milestone that underscores the company's leadership in health and fitness. Typically, smartwatches are marketed as consumer devices, not medical ones needing clearance.

These features will be available to U.S. customers later this year, but Apple did not say when it would make it to the rest of the world.

In addition, Apple said the Series 4 Apple Watch will also be able to detect when someone falls—and can tell the difference between a trip and a fall. If it detects a fall and the user doesn't respond in a minute, it'll automatically call for help. This feature may be especially attractive to older people or those with elderly parents worried about falling when no one is around to help.

  • Phil Schiller, Apple's senior vice president of worldwide marketing, speaks about the new Apple iPhone XR at the Steve Jobs Theater during an event to announce new Apple products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • Jeff Williams, Apple's chief operating officer, speaks about the Apple Watch Series 4 at the Steve Jobs Theater during an event to announce new Apple products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • Phil Schiller, Apple's senior vice president of worldwide marketing, speaks about the new Apple iPhone XS, iPhone XS Max and the iPhone XR at the Steve Jobs Theater during an event to announce new Apple products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • Apple CEO Tim Cook speaks about the Apple iPhone XS at the Steve Jobs Theater during an event to announce new Apple products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • Kaiann Drance, Apple's senior director, iPhone Worldwide Product Marketing, speaks about the Apple iPhone XS at the Steve Jobs Theater during an event to announce new Apple products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • Phil Schiller, Apple's senior vice president of worldwide marketing, speaks about the Apple iPhone XS at the Steve Jobs Theater during an event to announce new Apple products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • Phil Schiller, Apple's senior vice president of worldwide marketing, speaks about the Apple iPhone XS and Apple iPhone XS Max at the Steve Jobs Theater during an event to announce new Apple products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • Kaiann Drance, Apple's senior director, iPhone Worldwide Product Marketing, speaks about the Apple iPhone XS at the Steve Jobs Theater during an event to announce new Apple products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • Jeff Williams, Apple's chief operating officer, speaks about the Apple Watch Series 4 at the Steve Jobs Theater during an event to announce new Apple products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • Apple CEO Tim Cook speaks about the Apple Watch at the Steve Jobs Theater during an event to announce new Apple products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • Jeff Williams, Apple's chief operating officer, speaks about the Apple Watch Series 4 at the Steve Jobs Theater during an event to announce new Apple products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • Jeff Williams, Apple's chief operating officer, speaks about the Apple Watch Series 4 at the Steve Jobs Theater during an event to announce new Apple products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • Apple CEO Tim Cook speaks at the Steve Jobs Theater during an event to announce new Apple products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • Apple CEO Tim Cook discusses the new MacBook at the Steve Jobs Theater during an event to announce new products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • Phil Schiller, Apple's senior vice president of worldwide marketing, speaks about the new Apple iPhone XS, iPhone XS Max and the iPhone XR at the Steve Jobs Theater during an event to announce new Apple products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • Phil Schiller, Apple's senior vice president of worldwide marketing, speaks about the new Apple iPhone XS Max at the Steve Jobs Theater during an event to announce new Apple products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • Phil Schiller, Apple's senior vice president of worldwide marketing, speaks about the camera on the Apple iPhone XS at the Steve Jobs Theater during an event to announce new Apple products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • Jeff Williams, Apple's chief operating officer, speaks about the Apple Watch Series 4 at the Steve Jobs Theater during an event to announce new Apple products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • Phil Schiller, Apple's senior vice president of worldwide marketing, speaks about the camera on the Apple iPhone XS at the Steve Jobs Theater during an event to announce new Apple products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • CEO and founder of HomeCourt David Lee, right, and former NBA player Steve Nash talk about the Apple iPhone XS at the Steve Jobs Theater during an event to announce new Apple products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • Jeff Williams, Apple's chief operating officer, speaks about the Apple Watch Series 4 at the Steve Jobs Theater during an event to announce new Apple products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • Jeff Williams, Apple's chief operating officer, speaks about the Apple Watch Series 4 at the Steve Jobs Theater during an event to announce new Apple products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • People file into the Steve Jobs Theater before an event to announce new Apple products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • The new Apple iPhone XR is on display at the Steve Jobs Theater after an event to announce new products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • At the Steve Jobs Theater during an event to announce new products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • The new picture controls features are shown on an iPhone XR during an event to announce new products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • The new iPhone XR is displayed at Apple headquarters during an event to announce new products Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • The iPhone XS, left, and XS Max are displayed side to side during an event to announce new products at Apple headquarters Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)

  • The iPhone XS, right, and XS Max are displayed side to side during an event to announce new products at Apple headquarters Wednesday, Sept. 12, 2018, in Cupertino, Calif. (AP Photo/Marcio Jose Sanchez)