Adobe Edge Inspect Used while working on mobile/responsive sites to view natively on iPhone, updates in real time. https://chrome.google.com/webstore/detail/adobe-edge-inspect/ijoeapleklopieoejahbpdnhkjjgddem
Benchwarmer This has replaced my pinned Dribbble tab. "New tab" extension, no URL bar icon, transforms your new tab's background into a list of Dribbble popular/everyone/debut/following (you pick) shots. https://chrome.google.com/webstore/detail/benchwarmer-the-dribbble/lhdjhhpjicomphhjpehdhjenbaamdpnn
Bitly Used with custom .htaccess rule and vanity domain to shorten links with 2 clicks. https://chrome.google.com/webstore/detail/bitly-%E2%99%A5-your-bitmarks/iabeihobmhlgpkcgjiloemdbofjbdcic
Colllor This has replaced 0to255.com for me. Useful for finding just the right hex. https://chrome.google.com/webstore/detail/colllor/fnoilmekojpnaeflcgpificdgchalamn
LastPass I'm terrible with passwords, LastPass fixes that. Somewhat of a tricky setup, but once you get going you'll never go back. Tools to generate unique pw's, store credit card info to enter with a single click. The extension auto-populates username and password so you never have to remember it again. https://chrome.google.com/webstore/detail/lastpass/hdokiejnpimakedhajhdlcegeplioahd
LiveReload Page refreshes automatically on file save. Local or remote projects can be used. One of the best tools around. https://chrome.google.com/webstore/detail/livereload/jnihajbhpnppcggbcgedagnkighmdlei?hl=en
MagicScroll Web Reader I alternate between this and Readability, but have been using this more often when at my desktop. Readability more when needing to save to read later on phone. Enjoying the experience of using MagicScroll with Magic Trackpad. https://chrome.google.com/webstore/detail/magicscroll-web-reader/ecldhagehndokdmaiaigoaecbmbnmfkc
Screen Capture (by Google) Used when OSX screen capture won't cut it and you need a full-page (including everything off-screen) shot. Also, super easy for novices to install and use. https://chrome.google.com/webstore/detail/screen-capture-by-google/cpngackimfmofbokmjmljamhdncknpmg?hl=en
Text Free Browsing This is fun to use in various ways. Viewing Tumblr tagged search results to scan for media is pretty cool. https://chrome.google.com/webstore/detail/text-free-browsing/ioglfbphilinnhdmfbmfljmhemegfcdg/
WhatFont One of my favs. Turn it on and hover any text, it will pull the font-family from the CSS and display it above the cursor. https://chrome.google.com/webstore/detail/whatfont/jabopobgcpjmedljpbcaablpmlmfcogm
Window Resizer For testing exact screen sizes when working on responsive sites. https://chrome.google.com/webstore/detail/window-resizer/kkelicaakdanhinjdeammmilcgefonfh