Nexus 7 has received CyanogenMod 10.1 nightly build which is based on Android 4.2.1 Jelly Bean. CM 10.1 nightly build generates a new build daily with new improvements so there may be few bugs and issues and CM10.1 is an AOSP based ROM.
With nightly build users can experience Android 4.2.1 features such as Lock screen widgets, Swype-like typing, panoramic 360 photography, improved Google Now and more.
Install CyanogenMod 10.1 nightly build on Nexus 7
Take a complete backup of data,apps and settings as the procedure may wipe your data.
Make sure that the battery of device has a minimum charge of 60%.
Enable “USB debugging” on your device by going to Settings >> Developer options >> Enable USB debugging.
Bootloader on your device should be unlocked.
Clockwork Mod recovery should be installed.
You can go through the guide here to Backup, Unlock , Root Nexus 7.
Download CyanogenMod 10.1 nightly build for Nexus 7 and Google Apps package.
Copy the zip files to SD-Card of your device without extracting.
Switch off device and boot into recovery. Holding down Volume down and Power buttons simultaneously and using Volume buttons select Recovery mode.
Perform a Nandrop backup of your existing ROM so that you can revert later if things don’t work out well. Select “Backup and Restore” and then select “Backup” again.
Select “wipe data/factory reset” and confirm to wipe data. Wait till data gets wiped.
Select “install zip from sdcard” and select “choose zip from sdcard”. Navigate to ROM file and select to confirm installation. Wait for installation to get complete.
Select “choose zip from sdcard” again and select to install “Google apps package”.
CyanogenMod 10.1 (CM10.1) based on Android 4.2.1 is installed on Nexus 7.