MIT App Inventor
"MIT App Inventor is the fastest way to build apps for Android phones and tablets. Even with no prior experience, you can learn to build apps within hours. You'll learn from USF Professor David Wolber, who has been teaching beginners programming with App Inventor since its inception in 2009. With step-by-step video screencasts, Wolber starts with the basics then leads you through the development of successively more complex apps, teaching you programming concepts as you go."