Flagsmith - Flagsmith lets you manage feature flags and remote config across web, mobile and server side applications. Deliver true Continuous Integration. Get builds out faster. Control who has access to new features. We're Open Source.
Optimizely - A/B testing you'll actually use.
ConfigCat - ConfigCat is a developer-centric feature flag service with unlimited team size, awesome support, and a reasonable price tag.
VWO - Use VWO to tweak, optimize & personalize your website with minimal IT help.
Split.io - In a world where product development teams are pressured to do more with less, Split’s Feature Data Platform™ gives you the confidence to move fast without breaking things.
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.