Finally, search engine giant Google revealed the name behind the letter "M" for the Android M operating system (OS), which is now called Android Marshmallow. The operating system was initially unveiled during Google's I/O conference back in May of this year; and it is scheduled to be launched sometime this fall.

In addition, Google has already launched the complete version of the Android 6.0 SDK along with the software's final developer preview, which can be loaded, according to reports, on the company's Nexus 5, Nexus 6, and Nexus 9 devices.

According to The Verge, Google said in a blog post, "The preview images are near final but they are not intended for consumer use."

"Remember that when Android 6.0 Marshmallow launches to the public later this fall, you'll need to manually re-flash your device to a factory image to continue to receive consumer OTA updates for your Nexus device," Google added.

In terms of the features, the Android Marshmallow is expected to come with only eight permission categories. Also, users will now have the ability to either allow or refuse permissions to each application. Such include permitting or denying an app access to the device's camera. Users will also be capable of adjusting permissions at any time, according to reports.

Another new feature is called Doze, with which it can detect the device's activity or inactivity. This feature, Google claims, can increase battery life on devices.

Android Marshmallow supports fingerprint scanning features for recognition and user authentication such as when buying online on the Google Play Store, for example. It also supports the search engine giant's latest mobile wallet platform, Android Pay, including a support for USB Type-C port connection.

While Google plans to release its latest operating system for mobile and tablet devices, tech giant Apple Inc. is preparing to launch its new iOS 9 for its devices as well.