There are quite a few modules which are listed on node's github page but are not published with the npm-registry. These modules can't be installed using npm.
What is the correct way to install these nodejs modules after cloning them from Git?
You need to download their source from the github. Find the main file and then include it in your main file.
An example of this can be found here > How to manually install a node.js module?
Usually you need to find the source and go through the package.json file. There you can find which is the main file. So that you can include that in your application.
To include example.js in your app. Copy it in your application folder and append this on the top of your main js file.
var moduleName = require("path/to/example.js")