Today's applications are increasingly mobile. Computers are no longer confined to desks and laps but instead live in our pockets and hands. This course teaches students how to build mobile apps for Android and iOS, two of today's most popular platforms, and how to deploy them in Android Market and the App Store. Students learn how to write native apps for Android using Eclipse and the Android SDK, how to write native apps for iPhones, iPod touches, and iPads using Xcode and the iOS SDK, and how to write web apps for both platforms. This is OpenCourseWare, licensed by Dan Armendariz and David J. Malan of Harvard University under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 Unported License. Visit http://cs76.tv/2011/spring/ for more material, including prior semesters and other courses.