The first developer preview of Android O has recently been released, and it offers a lot of major updates. Almost two weeks ago, Google released the preview for the "Nexus 5X," "Nexus 6P", "Nexus Player," "Pixel C," and "Pixel" smartphone devices. A second preview is expected to be released in May, but no specific date has been announced yet.

A new video aimed at developers has also been published. It features Google's Nasir Khan, and on it, he said that with Android O, background services run minimally after the app has been backgrounded. The video runs for about six minutes, but it shares a lot of important and exciting features of Android O.

According to Android Headlines, one of the new features includes an alert when an app is displaying on top of another app. It gives users the capability to turn off the permission right from the notification itself - meaning you don't have to navigate to the apps menu to look for the app. This is Google's way of making the notification system more powerful and useful.

But it's more than just convenience. This is also a security feature because what many users are not aware is that apps have what you call the "draw over other apps" permission enabled. This cause battery life issues as well as issues as to how your device behaves. Android Nougat does not have notifications for these, and so users can install apps without knowing that this permission is automatically enabled.

Android Police said that with Android O, you can hide the notifications for the overlays on a per-app basis. Also, Android O will add support for "Neighborhood Aware Networking" for Wi-Fi, as well as an API for autofillers, and a Google Safe Browsing support for WebViews. Additionally, for the user interface, there is a new animation design every time you open and close the notification shade.