by Juan Leyva.
Hi Jaco,
what's the exact error you get?
In any case, for doing the CSS changes you can play with the online version here:
http://prototype.moodle.net/mobile/webappquiz/#/site/mm_courses
Or run in the app in the browser downloading the version from here:
https://github.com/moodlehq/moodlemobile-phonegapbuild
Here you have a tutorial: http://www.slideshare.net/juanleyva/creating-moodle-mobile-remote-themes
Juan