Killer features will indeed make the upcoming iPhone 5S and iPhone 6 release dates quite interesting, and a number of them got virtual confirmation with the fourth unleashing this week of iOS 7 in beta build.

One power feature, however, was hinted, thanks to a new report by MacRumors, detailing the ongoing works of Apple's so-called Boston research and development team, which directly points to "Siri improvements."

A More Functional Assistance from Siri

The objective was assumed because "Apple's Boston team is said to be made up of employees that formerly worked at VoiceSignal Technologies," reported MacRumors. The firm became an Apple affiliate when it was acquired in 2007 by Nuance, a partner of Apple, said the same report.

"Apple could potentially be working on a Siri solution that moves away from Nuance, (which is) the technology that currently powers the personal assistant," the report particularly said.

Siri, the popular PDA, which was lumped with the iPhone 4S debut, will reportedly show off more advanced capabilities such as better dictation prowess, improved pronunciation and a choice of male or female voice. They will be showcased via the iOS 7 launch scheduled on September 2013.

Improved Lock Screen

And around that time, more killer features for the iPhone 5S and iPhone 6 will be known, chief among them was a reconfigured lock screen as previewed Monday this week by the fourth beta release of the iOS 7.

While mostly bringing in stability and feature enhancements, the recoded mobile OS added "an arrow pointing right, located to the left of the 'slide to unlock' text," AppleInsider said in a report.

Part of the redesigned iPhone welcome screen was the altered "quick launch and notification centre graphics at the bottom and top of the screen, (which) been changed to straight lines rather than arrows, though they revert to arrows once the menus have been invoked."

Secured iPhone Thanks to Biometrics

And the last feature that was engineered to offer a more secure iPhone experience was the inclusion of a fingerprint scanner just beneath the handset's iconic Home key. This was seemingly confirmed by the discovery of "a folder within the latest beta for iOS 7 that is titled 'BiometricKitUI'," BGR News said in a report.

What was spotted comes with a "description of the UI (that says) a user being able to swipe the sensor on the iPhone's home button," BGR added. Analysts have been betting that Apple will pack its iPhone 5S home button with a new security mechanism that was acquired last year when the tech giant purchased the biometrics specialist AuthenTec.

The detection somehow supported the numerous assertion from analysts that a fingerprint scanner will be part of the so-called 5S killer features.

Apple watchers were convinced that the iPhone 5S will officially come out between Sept 20 and 28 this year, while the phablet-sized iPhone 6 is programmed for an early 2014 release date.