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.
SplitMetrics - SplitMetrics is the A/B testing platform for App Store and Google Play page to discover the most converting icons, screenshots, video, etc.
AddToAny - Share buttons by AddToAny, the universal sharing platform for websites and apps.
Intellimize - Convert more. Optimize and personalize for every website visitor.