Redmine-basecamp-theme-responsive is a project mainly written in ..., it's free.
A Basecame theme for Redmine.
Modified to support small display size. Optimised for mobile devices with screen width equal 480px.
To install, just clone into your Redmine theme dir like so:
$ cd /path/to/redmine/public/themes
$ git clone http://github.com/MartinSenovsky/redmine-basecamp-theme-responsive.git basecamp-responsive