Optimizely - A/B testing you'll actually use.
Moz - Backed by industry-leading data and the largest community of SEOs on the planet, Moz builds tools that make inbound marketing easy.
VWO - Use VWO to tweak, optimize & personalize your website with minimal IT help.
UpSeo - UpSeo is a best-in-class website traffic generator, allowing you to get more potential visitors to your website and enhance conversions.
Google Analytics - Improve your website to increase conversions, improve the user experience, and make more money using Google Analytics. Measure, understand and quantify engagement on your site with customized and in-depth reports.
SEO PowerSuite - Get all SEO tools in one pack - download free edition of SEO PowerSuite and get top 10 rankings for your site on Google and other search engines!