Unfortunately there is no GNU on iOS or Android. Every open a terminal on an Android phone and wonder why things just don't feel like the GNU/Linux systems you're used to? It's because it uses things like busybox instead of the GNU coreutils.
Sure, I have a very awesome computer that cost hundreds of dollars but I can't really use it because... somebody said so?
Zsh, bash, make, clang, SSH, Python, vim...
Their package selection is small compared to debian, but still quite nice.