Fitbug Member's Area is a large SPA (Single Page Application) coded in HTML5, CSS, JavaScript + jQuery, uses Handlebars.js templating engine, Underscore.js and a custom JS OOP framework.
Comunicates with the server's REST JSON API, authentication via OAuth.
Front-end utilises a heavily modified Twitter Bootstrap, LESS and HighCharts for some of the charts.
The app itself does 20+ different API requests, 15+ templates/partials...
Supports since IE8+.