MIT App Inventor Classic
The new App Inventor is now available at http://ai2.appinventor.mit.edu.
App Inventor is an web based application that allows you to create and test applications for the android devices. These devices include phones, tablets, appliances, TV's plus many more.
App Inventor is now available from MIT, you can Log in to App Inventor using your Google account.
Beginner App Inventor Concept Cards are some quick reference cards to specific commands
An App Inventor "textbook" from appinventor.org
Old links
What is MIT App Inventor Beta?
How to set up your computer.