In spring 2008, Hal initiated the first “Building Mobile Application” class at MIT (6.081). The first class used only the Android platform, and some of the class projects won prizes in the Android Developing Challenge. Future classes also involved other platforms such as Nokia and Windows Mobile. The class emphasizes not only programming, but also presentation skills. He is a visiting faculty member at Google, where he is part of the “App Inventor for Android” team, an educational program aiming to make it easy for people without programming background to write mobile phone applications and “explore whether this could change the nature of introductory computing”. He is the co-author of the book App Inventor with David Wolber, Ellen Spertus, and Liz Looney, published by O’Reilly Media in 2011.