Q-Stats - Get free marketing insights for every question on Quora.
Optimizely - A/B testing you'll actually use.
HypeStat - HypeStat is free statistics and analytics service, where you can find information about every website.
VWO - Use VWO to tweak, optimize & personalize your website with minimal IT help.
Site Rank Data - View historical rank information of websites via time series charts.
AB Tasty - AB Tasty is an all-inclusive platform for conversion rate optimization, personalization, customer activation, and testing.