How to log out of GREE
The only way to log out of GREE is through the GREE app. There is no option to log out from the BMP, MSB, or CD app.
To log out of your GREE account, first open your GREE app. Tap on the button on the top left with the three white lines. This brings up the menu.
In that menu, scroll/slide down to the very bottom, and tap on Settings.
Then at the very bottom of the settings menu is the Log out option.