On the last weeks we have been developing a facebook app using Drupal 7. People who connect to the app get notifications and emails which motivate them to action. We've built a responsive application, based on the Panopoly distribution. The theme was a sasson sub-theme.
The mobile version of the app was tested using the new saucelabs testing service. It's much faster to test it online, supports more configurations for complete cross-browser testing, and allows for automation. Much cheaper and better then CrossBrowserTesting.com.