This is a Spotify Playlist Analyzer, it makes an API authentication request with Spotify and retrieves the user playlist data. When a playlists is clicked it gives a more detailed description of the playlist including average tempo, song length, and some more fun data from Happiness, which is derived from Spotify's calculation for a song's valence. More info about Spotify's algorithms here.
There is a live demo available here: https://tkdallman.github.io/spotify-playlist-analyzer/
It was made with Vue.js and Nuxt with Vuex for state management
# install dependencies
$ npm install
# serve with hot reload at localhost:3000
$ npm run dev
# build for production and launch server
$ npm run build
$ npm run start
# pushes to GH pages
$ npm deploy
For detailed explanation on how things work, check out Nuxt.js docs.