iPhone 5S rumors suggest new features for the next iPhone. A fingerprint sensor scanner was discovered by developers in leaked iOS 7 beta software, and rumored to be used to unlock the iPhone. Other rumors suggest that the 5S release date is September 6, and will come in different colors.

Monday night, a beta version of iOS 7 was released to Apple developers, CNN reports. At least one developer found a file called "BiometricKitUI," which contained references to "fingerprint," according to reports by 9to5Mac and other blogs.

"You can then unlock your phone by putting your thumb on the home button. No longer will friends and family be able to pick up and peruse your phone -- no longer will you have to key in your passcode every time you want to do something," wrote Sebastian Anthony for Extreme Tech.

The next iPhone has been rumored to make use of fingerprint recognition technology, which Apple bought from AuthenTec, Forbes reports.

The text strings discovered in the iOS 7 beta software may describe the images in an on-screen tutorial instructing users how to touch the home button on an iPhone to scan their fingerprint to unlock the phone, Forbes reports. Apparently the image of a fingerprint appears on the screen and changes color during the recognition process.

Another source told 9to5Mac that "the technology is focused around unlocking the phone, so it is unclear if it is built for a payment system (as rumored) in the next iPhone."

Rumors are also suggesting that the next iPhone will be released earlier than any other iPhone, as early as September 6. According to translations of German blog iFun, a "credible and very serious source" said that the iPhone 5S could "come on the market" by September 6, which suggests it could be announced at the end of August, The Daily Mail reports.

Meanwhile, the iPhone 5S might be called the "iPhone 5C," according to The Christian Science Monitor. Chinese phone site WeiPhone posted a picture of what looks like retail packaging marked with "iPhone 5C" stickers.

And will the next iPhone be available in different colors? French site Nowhereelse speculates that the "C" stands for "colors," which fits earlier rumors that the lower-cost iPhone will come in several different shades, like the iPod.