After weeks of teasing, it's here: Google has officially unveiled Android 5.1 Lollipop. The new release focuses on support for features that usually depend on extra software to work, such as multiple SIM cards (handy for prepaid service in countries like China and India) and higher-quality HD voice calls on networks like T-Mobile or Verizon. You can control your WiFi networks and Bluetooth devices from the quick settings area, too.