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.
AppGrowthLab (by SplitMetrics) - 55 app growth lessons from 30 app marketing experts
Histats - Start tracking your visitors in 1 minute!
The Creative Marketer - Techniques & tools for copywriters, marketers, and creatives
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.
Gio UI - Gio is an open source library for creating portable, immediate mode GUI programs for Android, iOS, Linux, Windows, macOS.