Just copy and paste the following lines into a terminal:

git clone https://www.github.com/hiramvillarreal/iotpos
cd iotpos
sudo chmod +x install.sh
sudo ./install.sh
  
To start using the point of sale, in terminal type:

  iotpos
  
     * The default and only user and password is (without quotation marks):
     username: "admin"
     password: "linux"
  
To start using the administration module, in terminal type:

  iotstock
  
After reboot you can find the apps inside start menu>others

For an easy first time use, all security settings are disabled.