The mBack button works in three stages – just touching returns one position backwards, pressing mBack returns to the home screen and pressing and holding locks the screen. Viewing the most recently opened applications, for which pure Android has a separate button, here is done by swiping from the bottom of the display up. See more in „The Evolution of mBack“.
To save a copy to a computer, connect the two devices via a USB cable, find the Backup folder in your phone’s File Manager and transfer it to your computer.
Sometimes you may have to force the phone to restart if the device hangs due to improper execution of any of the applications. Then hold down the power button on the device for a long time – more than ten seconds.