Optimizely - A/B testing you'll actually use.
Optmyzr - Optmyzr AdWords Tools. Optimization Solutions, Quality Score Tracker, Landing Page Checker, and more. Free Trial Available.
VWO - Use VWO to tweak, optimize & personalize your website with minimal IT help.
Crazy Egg - Through Crazy Egg's heat map and scroll map reports you can get an understanding of how your visitors engage with your website so you can boost your conversion rates.
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.
Freshmarketer - An all-in-one CRO suite.