Free Bootstrap theme resembling Material Design.
Bootswatch offers Sass and Less files, so the theme can easily be integrated into your usual Rails application.
Implements only Bootstrap features which means that some Material stuff is missing, but also that you can easily use or replace the theme.
Also check out their other themes which can be used in a similar fashion.
Your development team has a full backlog of feature requests, chores and refactoring coupled with deadlines? We are familiar with that. With our "DevOps as a Service" offering, we support developer teams with infrastructure and operations expertise.