With the install of this android app you will get Debian Jessie.
Here are some tips:
-You do not need to root your device, it will work fine with any stock ROM.
-You will need 900 Mb free on internal storage. This app cannot be installed to SD card.
-A mouse or stylus is highly recommended.
You must know that Android 6.0 Marshmallow is not supported yet (apt-get and dpkg do not work).