We knew that it was coming soon after references to 5.1 appeared on several occasions. And sure enough Google just made Android 5.1 official. This should be a welcome update to the world’s most popular smartphone platform.
It features mandatory stability and performance improvements, but also brings support for multiple SIM cards. The new software should make it easier for multiple users to share a dual-SIM smartphone or for a single user to use multiple carriers’ services. With that in mind, we really don’t know how Android 5.1 is better at juggling multiple SIMs.
You will also get enhanced Device Protection mechanisms in Android 5.1. Lost or stolen devices will remain locked until the original user logs in with their Google account credentials. The lock stays in place even after a factory reset.
It also brings support for HD voice calls. Owners of compatible phones will have crystal-clear voice calls, as long as their carrier supports the feature. Some minor new features include the option to join Wi-Fi networks and control paired Bluetooth devices from the Quick Settings menu. We certainly like what we are hearing so far. More details should surface soon and when they do, we will let you know right away.
Source Phone Arena