MusicTester Dynamic Analyzer app allows you to assess the dynamic content of music tracks that you drag in to the browser window. The music is not uploaded anywhere. It is analyzed and displayed on the fly on your own computer.
Try Musictester here: http://musictester.net/demo
The app requires that you use a web-browser supporting the Web Audio API such as Chrome or Safari. Many smart-phones and tablets running Android or Apple iOS are supported. Firefox, Opera and Internet Explorer are currently not supported.