• by Mark Walsh  @markfwal, September 10, 2013

As expected, Apple launched a pair of new iPhone models simultaneously on Tuesday in a bid to capture customers at both the high and lower ends of the burgeoning global smartphone market.

The iPhone 5S -- the latest high-end version of Apple’s signature product -- features a fingerprint scanner in the home button for enhanced device security. The cheaper iPhone 5C, made of plastic and aimed especially at emerging markets like China and India, will start at $99 with a two-year contract -- half the price of the new 5S.

Without a contract, however, the 5C will start at $549, not as low as the $450 that some analysts had projected. 

Breaking from the traditional options of only black or white, both new iPhone models will come in a variety of colors: gold, silver and gray for the 5S, and white, red, blue, yellow and green for the 5C iPhone. The device also comes with an 8-megapixel camera and a new FaceTime camera and connects to high-speed LTE wireless networks.

The 5S is priced at $199 for 16-GB, $299 for 32-GB, and $399 for 64-GB. The new iPhones will be available for pre-order next week and will hit stores on Sept. 20.

Both new phones will ship with iOS 7, the striking redesign of the Apple operating system unveiled in June at the company’s Worldwide Developers Conference. The software upgrade includes iTunes Radio, the free new music service that allows users to create personalized radio stations and share them with friends.

By replacing the existing iPhone 5 “with not one but two new designs,” Apple CEO Tim Cook explained at the company’s media event today at its Cupertino, Calif., headquarters, the dual release “allows us to serve even more customers.”

That's especially critical for the tech giant as it loses ground not only to arch rival Samsung but lower-end smartphone makers like Huawei, Lenovo and ZTE. Surging demand for cheaper smartphones and slowing growth of iPhone and iPad sales have put Apple under growing pressure to launch a more affordable handset.

Apple’s share of worldwide smartphone sales in the second quarter slipped to 14.2% from 18.8% in year-earlier period, while Samsung increased from 29.7% to 31.7%, according to Gartner data. Worse, Android’s dominant share climbed to 79%, underscoring the uphill climb Apple faces in gaining back share.

While introducing a cheaper alternative, Apple is still likely to be judged by what it delivers in its flagship iPhone. In that regard, the James Bond-like fingerprint scanner is clearly the standout feature of the iPhone 5S, much as Siri was with the rollout of the iPhone 4S two years ago.

Called Touch ID, the much-rumored fingerprint sensor is designed to serve as more secure way to unlock a phone or authorizes purchases without having to rely on various passwords. Those with privacy concerns have the option to turn off the fingerprint scanner. Where it could get interesting is if Apple allows developers to incorporate the technology into apps.

The Wall Street Journal reported this week that Google plans to release a similar fingerprint scanner on new smartphones  running its Android system later this year.

The aluminum-bodied 5S iPhone also packs a new chip called M7 that can monitor motion, and would enhance the ability of applications to keep track of a user’s movements throughout the day. Other new features include better battery life and a new camera system that includes a larger aperture, improved flash, and image stabilization.

They will also be launched concurrently for the first time in China, where Apple hopes the 5C in particular will appeal to more cost-conscious consumers. Apple is reportedly close to a distribution deal with China Mobile that could boost its prospects in the world’s largest wireless market. For the first time, Apple is also holding a media event in Beijing nine hours after the presentation at its U.S. headquarters.

Also, Siri -- the virtual assistant -- is getting a new female voice and an added male voice in iOS 7. It will also be able to respond to new commands like looking something up on Wikipedia or other sites. In addition to the new iPhones, iOS7 will be released next month to everyone with an iOS device -- 700 million iPhones, iPads and iPods.