A couple of demos of user tracking with JavaScript.
I show some methods how to send user data back into the server. More details in my blog article (in Chinese).
First, clone the repo.
$ git clone https://github.com/ruanyf/user-tracking-demos.git
$ cd user-tracking-demos
Install the dependences, then launch the server.
$ npm install
$ node server.js
Visit http://localhost:3000 in your browser. Follow the instruction on the page, then watch what happens in the commandline.