'''App Inventor''' is a cloud-based Android apps-development platform. It was developed at Google Labs and is now maintained by the Media Lab at the Massachusetts Institute of Technology (MIT). It uses a graphical drag-and-drop interface to connect programming blocks which have the appearance of puzzle pieces. The intent is to use this tool as an introduction to programming for non-programmers as well as to build real-world applications.
See also the Wikipedia article for more information.