Snowpack is a post-install tool. It runs after npm install, and it essentially exists to convert your npm packages (in your “nodemodules/” directory) into JS files that run in the browser without a bundler (written to a “webmodules/” directory). Creating a sample app In this tutorial we are going to create a simple demo app which is going to make use of a library called finance. We are going to create an app to calculate simple interest from principal, rate and time.