The preview of Android M, successor to Android 5.0 Lollipop, is available now to developers and holders of Nexus 5, Nexus 6, Nexus 9 and Nexus Players.

Google will offer developer previews of Android M, up until it reveals what dessert that "M" stands for and launches the OS in the third quarter of this year. The first developer preview will be followed by two others; the second one arrives in late June or early July and last arriving late July.

With this set of developer previews, users won't have to flash their devices to receive patches and updates.

"To make the process easier, we'll deliver updates over-the-air (OTA) to devices already flashed to a Preview build, as well as providing system images that you can download and flash manually," says Google.

There aren't sweeping changes to the OS' user interface this time. But there have been changes to the app drawer, lock screen and the menu layout. The app menu now scrolls horizontally and there appears to be a listing of commonly used apps at the top of the menu.

Android M also brought with it a significant upgrade to Google Now. Google Now on tap expands the search engine company's digital assistant service to deliver more information without requiring users to leave whatever apps their using.

"We're working to make Google Now a little smarter in the upcoming Android M release, so you can ask it to assist you with whatever you're doing-right in the moment, anywhere on your phone," says Google's Aparna Chennapragada, director of product management.

In those instances when more information is needed, Google Now on tap users need only hold their handsets' home button in order to find about the type of dress required for that restaurant a friend suggested or to find those lyrics to that song that other friend keeps quoting.

"When you tap and hold the home button, Google gives you options that are a best guess of what might be helpful to you in the moment," says Chennapragada. "But if you need something specific, you can also get Google to help by saying 'Ok Google' from any screen, and any app."

In the current build of the Android M developer preview, Google Now on tap appears to be limited in its functionality. But that could change with the next preview and it'll assuredly be at full force this fall.