According to the post from official blogspot of Android, Google has announced the Android 5.1, to improve stability and performance for Lollipop. It also offers new features such as support for multiple SIM cards, HD voice and Device Protection.
Support for Multiple SIM cards ?
It’s finally that Google’s Android 5.1 is now letting you to use more than one SIM card on a phone if your device has multiple SIM card slots.
This feature with the same function already available in Apple’s iOS for a while and now it’s Android turn. In case of lost or stolen, your device still remains locked and only open again until you sign in with your Google account, even reset to factory settings.
There’s no clarify that if it’s work if someone flash the device’s firmware. But this new security feature will be available in most Android smartphones and tablets, including Nexus 6 and Nexus 9.
High Definition Voice Calling
Android 5.1 now supporting HD voice calling and available between compatible devices such as Nexus 6 on Verizon or T-Mobile carriers.
With this update, it also brings a lot of enhancements like you can join Wi-Fi networks or control of your paired Bluetooth devices from Quick Settings.