Apple is in the process of finalizing iOS 8 development with the release of Beta 6 to a select group of testers.

On Tuesday, Aug. 18, BGR reported that Apple barred average developers from getting Beta 6 because the company was close to releasing the Golden Master - a term developers use to describe finished products. Instead, Apple will concentrate on working with a chosen few.

The same report also said that testers rejected the sixth beta on Monday because the software caused YouTube to no longer work on the Safari internet browser. Apple is allegedly requiring unanimous approval from its testing partners by Sept. 5.

This deadline comes just a few days before the iPhone 6's rumored unveiling on Sept. 9. Apple's newest smartphone is expected to be running on the iOS 8 operating system upon release. It is likely both these products will be introduced at the same time, even though Apple has yet to confirm their release.

Besides the iPhone 6, other mobile devices will be getting the next-gen iOS 8 software. Those devices include the iPhone 4s, iPhone 5, iPhone 5s, iPhone 5c, iPad 2, iPad Mini, iPad Mini with Retina Display (a.k.a. 'iPad Mini 2)', and the fifth-generation iPod.

Absent from the list of devices getting the new update is the iPhone 4 smartphone as well as the original iPad tablet. Both devices were released four years ago, which is old by mobile device standards.

Previously, subscribed developers were given access to the latest iOS 8 betas. In many instances, these betas were released to average consumers via third-party sources. Testing for iOS 8 beta began when it was revealed for the first time at WWDC 2014 in June.

Beta 6 will be the last trial version before the iOS 8 public release, which may come next month. Top features coming with the ultimate release include the QuickType keyboard function, new travel time notification feature, enhanced privacy, better battery management, health app, and family sharing features.