Android 5.0 Lollipop was unveiled at Google I/O in June 2014 and then first rolled out to Nexus devices in October.

We're expecting a similar timeframe for the latest update, with Google's Nexus devices first to get Android M followed by other flagship phones and tablets in late 2015/early 2016.

We'll update this article when we find out exactly which smartphones and tablets will be getting Android M and when, but for now we do know that the Nexus 5, Nexus 6, Nexus 9 and Nexus Player all have confirmed Developer Previews so will be among the first devices to get the update.

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For now, though, you can already download Google Photos, the company's new free and unlimited way to back up all of your photos. Find out more in our What is Google Photos article.

What's new in Android M?

You can find out everything there is to know so far about the new features in Android M in our Android M article, but below is a brief overview of what to expect when your smartphone or tablet finally does get the update.

Android M is more of an incremental upgrade that aims to polish up the operating system to make it smooth and shiny and get rid of all the bugs.  There are six main areas of concentration: App Permissions, Web Experience, App Links, Mobile Payments, Fingerprint Support and Power & Charging.

Google Doze is a new power saving feature, there's support for USB Type-C and fingerprint sensors, a new Now on Tap feature for Google Now and more.

We still don't know what Android M is going to be called, but possibilities include Milkshake and Marshmallow.

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