Google has unveiled Android O, the latest iteration of the firm's mobile operating system, with a preview version released for developers. The developers' OS showcases several major changes in store, ahead of the system's official presentation at the Google I/O conference in May.

Google promises to boost device battery life with Android O by restricting the activity of applications running in the background, making them more power-efficient and less battery-draining. A new autofill function will be able to store data such as usernames, passwords, addresses or credit card details and automatically fill out forms. Plus, the update brings "Picture in Picture" (PiP) display capabilities for watching a video while using other apps alongside.

Android O overhauls notifications too, allowing developers to create themed notification channels, grouping alerts from various apps so users can decide which ones they receive. In general, users will have greater control over notifications and which ones they want to see displayed onscreen. The number of notifications per app will also be displayed, as in iOS. Another visual change comes in the form of adaptive icons, matching the icon style to a user's particular version of Android, with more rounded or square icon designs in the various manufacturer interfaces.

Google has already stated that Android O will support the latest version of Java (8) as well as new wireless technologies like Sony's LDAC codec for Hi-Res audio.

This latest version of Android is expected to land in Google's latest Pixel smartphones before progressively rolling out from fall this year. Google is yet to announce which sweet snack will lend its name to the latest OS. After Android KitKat, Lollipop, Marshmallow and Nougat, could it be time for an Android Oreo?