I was just playing about with the RFDuino and made a small app to stream tweets and flash a light on the arduino for each one that comes through. Twitter developer account required to try it out! I'll be cleaning it up and adding it to the app store in afew weeks.
====== ##Running The App
You'll need to navigate to the where you've downloaded the project and run a pod update:
pod update
The RFduino sketch can be found in NotifySketch.