This plugin lets you listen for when a CSS property, or properties, changes on element. It utilizes Mutation Observers to mimic the DOMAttrModified (Mutation Events API) and propertychange (Internet Explorer) events.

There is both a jQuery-specific plugin as well as a library agnostic version of this plugin available.

bower install darcyclarke/watch.js --save

This library utilizes the Polymer team's Mutation Observers and WeakMap Polyfills. They are included by default which bulks the library a bit. Depending on future usage, I may choose to references these as bower dependancies.