Chrome (65) DevTools has a great new feature called Local Overrides. It allows overriding CSS, JS and DOM on any live site.
We use DevTools to tweak styles, test layout changes right in the browser all the time. With Local Overrides, we can keep these changes even if live page reloads.
Quick Tip(s): Using CSS to hide button text
Mule MUnit - Tips for Writing Unit Tests
Export Data From Views to CSV File