Optimizely - A/B testing you'll actually use.
Lander - Lander is a powerful online tool to create Landing Pages.
VWO - Use VWO to tweak, optimize & personalize your website with minimal IT help.
Inbound Now - Build Landing pages, manage inbound leads, and create calls to actions to improve marketing with our Inbound Marketing Plugins for WordPress
Chartbeat - Chartbeat shows you real-time traffic to your website and allows you to set alerts for any downtime or spikes in traffic.
Pagewiz - An innovative landing page platform that lets you create, publish, and split-test landing pages.