LeanPlum - Mobile A/B Testing for Native iOS and Android Apps
Optimizely - A/B testing you'll actually use.
Splitforce - Splitforce A/B testing for iOS, Android, and Unity mobile applications.
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.
Taplytics - Mobile A/B testing for everyone. With the world's most fully featured mobile A/B testing platform.
VWO - Use VWO to tweak, optimize & personalize your website with minimal IT help.