อัปเดตเมื่อ Aug 3, 2018
GNURoot Debian has not been maintained in over a year and is broken in many ways.
So, I am sending new users to a new app called UserLAnd which has a paid active dev team, but is still open and does most of what GNURoot Debian did, but better.
You are now sent to UserLAnd in the following cases:
1) you are using android 8.0+, because GNURoot Debian is completely broken for those users.
2) you are creating a new rootfs (unless coming from GNURoot Octave or GNURoot Runescape Installer)