AB Tasty - AB Tasty is an all-inclusive platform for conversion rate optimization, personalization, customer activation, and testing.
Site Rank Data - View historical rank information of websites via time series charts.
Optimizely - A/B testing you'll actually use.
Q-Stats - Get free marketing insights for every question on Quora.
BEYABLE - Real-time personalization solutions for e-commerce & lead gen websites
HypeStat - HypeStat is free statistics and analytics service, where you can find information about every website.