The latest Lollipop incarnation may have been around for more than a month now, first arriving on Android One smartphones slated for Indonesia, but Google only yesterday made the official announcement and revealed the much-awaited changelog.
The good news doesn't end there, as the search giant also released a number of Android 5.1 factory images.
Android 5.1 Lollipop packs some pretty major changes (opens in new tab). Among them are support for multiple SIMs, a feature that lots of Android vendors have offered for years now, and Device Protection, a feature designed to deter smartphone theft.
When enabled, Device Protection will lock the device, and only allow the original owner (the person last logged in with a Google account, to be exact) to re-enable it. It seems to work similarly to Find My iPhone, although this feature is limited to Nexus 6 and Nexus 9 as well as Android 5.1 devices - which are far and few between right now.
Now what about those factory images? Well Google has, so far, released Android 5.1 factory images only for Nexus 5 (opens in new tab), first-generation Nexus 7 (opens in new tab) (Wi-Fi model only), and Nexus 10 (opens in new tab). It's an odd mix, but more devices will soon join the list.
Of course, if there's an Android 5.1 factory image available for your Nexus device you can now get the second Lollipop iteration up and running on your device. You have two options. One, you can make a clean install. And two, you can use the factory image to perform an upgrade.
Of the two options, I recommend the former as it's the least likely path to give you headaches after the process (not including having to restore your data and the like).
Upgrading through the factory image is not something that Google would like you to do, although possible. That said, I have had good results the last couple of times I used this option.
If you want to learn more, check out my detailed how-to guide (opens in new tab) on installing and updating to Lollipop, which takes you through both options in detail. It also includes information on how to use over-the-air update files.