A (very long) while ago a bought the flipmeacoin.com domain. For a bit it allowed you to flip a virtual coin (using Threejs & Physijs). Things have since moved on and consequently, I think the site stopped working a while ago. Physijs.js seems to be pretty much defunct now (last update 2015!), and three.js is quite fickle about version changes.
The issue was using the latest versions of js libraries from CDN. Lesson learnt.
Code for the new version is all accessible in the browser as view source. Please feel free to use the code as you will … license is WTFPL. But if you do something cool, tell me.
Why not on Github?
I replaced Physijs with Enable3d, which uses ammo too.
How random are flips?
Tough question. Work in progress.
At the time of publishing the answer is – pick heads (if you are using Chome browser on Windows)!