Website Grader - Grade your website's strengths and weaknesses in seconds.
Optimizely - A/B testing you'll actually use.
PageSpeed Ninja - One-click page speed boost for WordPress
VWO - Use VWO to tweak, optimize & personalize your website with minimal IT help.
WebSite Auditor - The techie's SEO spider: find site issues other tools miss
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.