Algolia - Algolia's Search API makes it easy to deliver a great search experience in your apps & websites. Algolia Search provides hosted full-text, numerical, faceted and geolocalized search.
Optimizely - A/B testing you'll actually use.
Hawk Search - Site-search engine for eCommerce platforms.
VWO - Use VWO to tweak, optimize & personalize your website with minimal IT help.
SE Ranking - All-in-One cloud-based SEO software for agencies, marketing teams and webmasters
Google Analytics - Improve your website to increase conversions, improve the user experience, and make more money using Google Analytics. Measure, understand and quantify engagement on your site with customized and in-depth reports.