This is a project I have been working on a while called Tappt. Tappt is a frontend for your kegerator which tracks temperature and the beer in your keg.
The hardware is built using an Arduino Uno, a NFC shield, and a WiFi shield. For the app I am using Android but I will port this to iOS and windows phone. The backend and website were written using ASP.Net MVC 4 and WebApi as well as Angular.js.