GNURoot Debian provides a method for you to install and use Debian and its associated applications/packages alongside Android.

This does NOT require root.
A regular uninstall fully cleans up after this application.
This is expandable and you will be able to install your own applciations/packages into it.

Inside GNURoot Debian you can create a root file system launch into it or delete it.

The moto is: "This ain't done until everything* will run"
*everything == all linux user space applications without having to root your device. Some things (a small number of things) that actually require root will not work (like inserting a kernel module).

Please: file bugs feature requests of view code here:
https://github.com/corbinlc/GNURootDebian

This work is now sponsored by Teradyne!