Optimizely - A/B testing you'll actually use.
VWO - Use VWO to tweak, optimize & personalize your website with minimal IT help.
Evolv - Evolv is the visual editor for web-based projects that are used to find better ways to connect with customers in order to improve marketing economics.
SplitMetrics - SplitMetrics is the A/B testing platform for App Store and Google Play page to discover the most converting icons, screenshots, video, etc.
Chartbeat - Chartbeat shows you real-time traffic to your website and allows you to set alerts for any downtime or spikes in traffic.
UserReplay - Customer experience management software for improving conversion rates.