Use NPR HTTP API and  service to retrive data
Basic Angular expressions
ng-init and ng-click
ng-show and ng-hide
ng-repeat, looping through an array and an object
Rough audio playback based on NPR data
Basic directive to encapsulate data presentation and playback
Introduce services, here a Github throttled call that retrieve info about a user
Encapsulate audio and player in services and display button and audio data
Encapsulate calls to NPR to its own service