I wrote this to save myself some time whilst supporting Flexbox in several different browsers. You can use Autoprefixer if you wish but I like having a simple build process and found Autoprefixer at the time to be a little buggy whilst using Flexbox.
bower install sass-flexboxy --save
display-flex();
justify-content($justified-value);
align-content($align-content-value);
align-items($align-items-value);
align-self($align-self-value);
flex-direction($direction-value);
flex-wrap($wrap-value);
flex-wrap($wrap-value);
flex($flex-value);
flex-basis($size-value);
order($order-value);
flex-grow($grow-value);
flex-shrink($shrink-value);