The Pi Power Board is a tiny add-on board for the Raspberry Pi

It consists of a DS3231 RTC, an Attiny85, a 3A Buck converter and a fan
It permits to power on and off the Raspberry via an extra 12v wire, let alone the 12v an GND wires

it's born to ease the install of a Raspberry Pi in a car (dashboard, media player, carPc)

To install and have a fully working board we have to fulfill 4 steps:
Enable I2C communications
Check the I2C, Rtc and Attiny are working
Enable the Real Time Clock
Install the PiPowerBoardScript as an autostart script

Let's start from the I2C communications:
Open the Menu->Preferences->Raspberry Pi Configuration
Go to the Interfaces tab and enable I2C, "OK" and reboot
on Reboot open a terminal and install:
sudo apt-get install -y python-smbus i2c-tools

after install try (on terminal):
i2cdetect -y 1

You Raspberry should show a matrix with two numbers, 68 and 26
If they show we're on track!
Now, for the RTC config I found a very well written page I should point:
https://www.raspberrypi-spy.co.uk/2015/05/adding-a-ds3231-real-time-clock-to-the-raspberry-pi/

PiPowerboard Script install:
download the script "PiPowerBoardScript.py" and save it in your "home/pi" folder
open a terminal and edit your "/etc/xdg/lxsession/LXDE-pi/autostart":
e.g. sudo nano /etc/xdg/lxsession/LXDE-pi/autostart
paste this line "/usr/bin/python /home/pi/PiPowerBoardScript.py"
after the "@pcmanfm..." line

save and reboot

Now try a commanded power on and shutdown, everything should be ok!