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.
Heurix.io - Heurix is a free heuristic evaluation tool that helps you work out how to improve your website.
StatCounter - StatCounter is a simple but powerful real-time web analytics service that helps you track, analyse and understand your visitors so you can make good decisions to become more successful online.
UX Companion - A handy glossary of UX theories, tools and principles (iOS)
Histats - Start tracking your visitors in 1 minute!
Heurio - Do website reviews faster. Heurio eliminates the administration process and lets you focus on creating value in a collaborative and user-friendly way. Perfect for heuristic evaluation, design and development review, bug report, QA testing and more.