Nexus 7 is powered by a 1.2 GHz quad-core Cortex-A9 processor, 1 GB RAM and has 8 and 16 GB internal storage options. It has a 1.2 MP rear camera and 4325 mAh battery. It ran on Android 4.1 at the time of its launch but it can be officially updated to Android Lollipop.
Paranoid Android 5.1 ROM has hit quite a few Nexus devices. Nexus 7 2012 has also received it. If you are bored of stock ROM then you can install Paranoid Android ROM on WiFi version of Nexus 7 2012. Follow the detailed guide given below.