AddThis - AddThis free website tools include share buttons, targeting tools and content recommendations help you get more likes, shares and followers and keep them coming back.
Optimizely - A/B testing you'll actually use.
Sharingbuttons.io - Quickly generate social sharing buttons with a tiny performance footprint.
VWO - Use VWO to tweak, optimize & personalize your website with minimal IT help.
AddToAny - Share buttons by AddToAny, the universal sharing platform for websites and apps.
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.