The new rendition initially is being recommended only for mobile app makers and will only work on a few smartphones and tablets. Google usually hasn't released test versions of Android until its annual developers' conference. The event begins May 18 this year.

The upgraded software, known as 'Android N' for now, offers a split-screen feature so users can toggle between apps and the ability to reply directly to notifications. Those options are already on the operating system that runs Apple's iPhone.

Although Android powers most of the world's smartphones, it often takes years before consumers install upgraded versions of the software.