Browsersync - Browsersync makes your tweaking and testing faster by synchronising file changes and interactions...
History Search - History Search remembers what's on all those websites you visit so you can find them again.
LiveReload - LiveReload 2 proudly presents… The Web Developer Wonderland. (a happy land where browsers don't need a Refresh button). CSS edits and image changes apply live. CoffeeScript, SASS, LESS and others just work.
Microsoft Web Activities - Microsoft's new extension bringing timeline to Chrome
Ghostlab - Ghostlab allows you to test out a newly developed website on a variety of browsers and mobile devices at the same time. To get started, simply drag the web address to the Ghostlab system and press the play button. Read more about Ghostlab.
Ruin My Search History - Ruin your Google search history with a single click