My Favorite Muni is a project developed with the Ionic Framework and AngularJS.
MyFavoriteMuni allows users to save their favorite transit stops and easily get prediction data from the NextBus service. I have only tested the NextBus API with San Francisco's MUNI system, but I have found it to be more accurate than other systems (ie Google) so I hope others find it to be useful as well.
The application is currently in a beta test and will be released on the Google Play Store shortly with an iOS release following that.
Prediction data is provided by NextMuni.com by means of ProximoBus's JSON API (http://proximobus.appspot.com/).