This is a prototype mobile-friendly sphinx theme I made for readthedocs.org. It's currently in development and includes some rtd variable checks that can be ignored if you're just tyring to use it on your project outside of that site.

Symlink the sphinx_rtd_theme/sphinx_rtd_theme repository into your documentation at docs/_themes/sphinx_rtd_theme then add the following two settings to your Sphinx conf.py file:

html_theme = "sphinx_rtd_theme"
html_theme_path = ["_themes", ]

To work on this theme you'll need to install bower. Then simply run a bower install in the root directory to install the dependencies. Once installed, make your sass changes to the sphix_rtd_theme/sass directory, making sure to use compass to compile down to css.

If you'd like to see your changes made to master, send me a pull request.