https://github.com/dgelessus/fistutils
These are distutils, setuptools and pip modified to run on Pythonista. They "work", i. e. you can run setup.py files, and pip can manage pure Python packages properly. Non-Python modules still don't work of course, and a few other things are less than ideal. Full details on what does and doesn't work can be found in the README.
This has not been tested very much, I thought it's probably better to post it now than to have it lying around on my iPad. As usual, any feedback, bug reports and pull requests are welcome!