SASS home site
http://sass-lang.com/
SASS apps:
CodeKit (Paid)
Compass.app (Paid, Open Source)
Ghostlab (Paid)
Hammer (Paid)
Koala (Open Source) - http://koala-app.com/
LiveReload (Paid, Open Source)
Prepros (Paid) - https://prepros.io/
Scout (Open Source)