Social Mention by BrandMentions
https://brandmentions.com/socialmention/Social Free real-time social mentions search & analysis Social Mention finds who’s talking about your brand or competitors in the news & social media It also offers real-time social media search and analysis. Enter a search term and see who’s sharing what, right now.
Bing Webmaster Tools
http://www.bing.com/toolbox/webmasterTools Suite, Diagnostic Similar in function to Google Webmaster Tools, Bing offers a suite of interesting research tools and resources for webmasters.
Bitly
https://bitly.com/Social, Analytics Most people use Bitly for URL shortening, but the real power of this platform comes from its analytics.
Boomerang
http://www.boomeranggmail.com/Email, Productivity Boomerang lets you follow up on emails, even when you forget. Great for link building or any time you send a lot of emails.
Buffer
https://bufferapp.com/Social Optimize your online social media sharing. Buffer allows you to share with your audience at the optimal times for greater visibility.
BuiltWith
http://builtwith.com/Competitive Intelligence Use BuiltWith to discover what technology nearly any website was, well, built with. Great for competitive intelligence as well.
Buzzstream Tools Suite
http://tools.buzzstream.com/link-buildingLink Building, Tools Suite, Email Most people know Buzzstream as an outreach platform, but they also offer a number of free link-building tools. This company gets it.
Caption Tube
http://captiontube.appspot.com/Video Free and easy resource used to create captions for YouTube. Helps with usability and offers viewers a readable transcript.
CircleCount
http://www.circlecount.com/Social, Analytics Google+ analytics ramped up. Free resource to track your followers and analyze your shares. See how many followers you’ve gained over time.
Content Strategy Generator Tool
http://seogadget.com/content-strategy-generator-tool-v2-update/Content This tool from SEOgadget helps you plan your content strategy intelligently, using keyword research and estimating your audience size.
Convert Word Documents to Clean HTML
http://word2cleanhtml.com/Content, Productivity Despite the rise of Google Docs, Word still dominates much of the world. Copying and pasting has always been a hurdle, but this tool makes it easy.
Copyscape
http://www.copyscape.com/Content Copyscape serves both as a plagiarism checker and a duplicate-content checker. Great to use if your content has been distributed across the web.
Domain Hunter Plus
http://domainhunterplus.com/Link Building This magic extension for Chrome not only helps you find important broken links, but also tells you if the links point to an available domain.
http://www.easel.ly/Infographics Free tools for creating and sharing inforgraphics. The templates allow anyone to create a professional-looking graphic.
Email Format
http://email-format.com/Email, Productivity Email Format helps you find the proper structure for thousands of companies and organizations across the web.
FindPeopleonPlus
http://www.findpeopleonplus.com/Social The ultimate Google+ directory that’s great for research, outreach, and link building. Sort by keywords, profession, country, and more.
Frobee Robots.txt Checker
http://www.frobee.com/robots-txt-checkRobots.txt, Technical SEO Many robots.txt files contain hidden errors not easily visible to humans. Run your file through this tool and you never know what you’ll discover.
GetListed
https://getlisted.org/Local, Moz This awesome local SEO tool scores your local SEO visibility and gives you actionable next steps to raise your score.
Google Keyword Planner
http://adwords.google.com/keywordplannerKeyword Research The tool to replace Google’s popular keyword tool has been derided by some, but still offers data not available anywhere else.
Google Analytics
http://www.google.com/analytics/Analytics The most popular of all the analytics tools available, Google Analytics continually innovates and sets the standard.