Install Google Play

Because RECOVRY from AOSP that can't not install GAPPS (ex: failed to verify whole-file signature" "E: signature verification failed" "installation aborted").

So we need to install another RECOVERY (ex: ClockWorkMod)

1. Downalod(Nexus 7 link ( or download another in webSite) and install CLockWorkMod RECOVERY

Install command:

adb reboot bootloader
fastboot oem unlock
fastboot flash recovery recovery-clockwork-6.0.4.3-grouper.img

1. Download GAPPS.

The GAPPS has many different packages (ref: OpenGAPPS), I install the simplest packages(gapps-custom-pico-4.3) from an unkown web-site Then install GAPPS File

1. Install GAPPS within commands install command(Note: mobile must into recovery and sideload first)

adb sideload gapps-custom-pico-4.3.zip

1. Install GAPPS within AOSP unzip GAPGGS files to OUT/target/product/'PRODUCT_NAME'/system

for example /home/jerome/WORKING_DIRECTORY/out/target/product/grouper/system

and reburn images to your devices.