By default Foundation for Apps uses Ruby Sass to compile your SCSS to CSS. This guide covers the conversion to libsass
I accept there are quite a few reasons that you might continue to use Ruby Sass, but if some of the missing features aren’t going to cause you any problems it’s much faster to compile using libsass. My compilation times dropped from around 8.3s using ruby sass to 1.4s using libsass. A huge benefit when you’re repeatedly waiting for your new style to show up during development. Continue reading