Compass.app is described as 'Compass is a stylesheet authoring framework that makes your stylesheets and markup easier to build and maintain'. There are more than 10 alternatives to Compass.app for a variety of platforms, including Mac, Windows, Linux, the Web and Self-Hosted solutions. The best alternative is Prepros. It's not free, so if you're looking for a free alternative, you could try Scout-App or Fire.app. Other great apps like Compass.app are CodeKit (Paid), Bourbon (Free, Open Source), Live.js (Free, Open Source) and kouto swiss (Free, Open Source).