Apps with WordPress using Backbone.js
To start with: WPTuts is always my first point to start from.
Using Backbone within the Admin (backend)
Using Backbone within the Admin (frontend)
Alex Bachuck: Displaying recent posts WordPress with Backbone.js
The recent post plugin is also available here.
A starting point for single page apps on Wordpress with Backbone.js and the json api plugin: WordPressSinglePage
Backbone Debugger – a chrome extension that let’s you see your views, models, collections and routers in realtime using Chrome Dev tools.
You can also at all the other resources at Peter R. Knight.