Recently I changed my workflow, using some of the best tools available: gulp.js, gulp-sass and Browser-Sync.
With phpThumbsUp, any image that is uploaded to the MODX manager will have various sizes automatically created. The phpThumbsUp extra will then check the screen with before loading the correct image on the front-end.
Foundation4-MODX is a MODX Revolution template based on Foundation 4 from Zurb. This is a very minimal MODX Revolution template, with this template you can quickly install to start using the fantastic Foundation 4 framework.
ThemesMODX, a project by Any Screen Size is selling premioum, responsive MODX themes for a great price.
Got to ThemesMODX