When Google App Inventor came out, Google advertised it as a groundbreaking Android app-development platform. One could integrate components to create awesome apps, or so it seemed from the promotional videos. However, it was a lesser-known fact at that time that the App Inventor project would die soon.
Nowadays, the App Inventor page reads,
App Inventor for Android lets people create apps for Android phones by manipulating programming blocks in a web browser. Since July 2010, Google has run App Inventor as a large-scale public web service as a part of its Google Labs suite. With the wind down of Google Labs, as of December 31, 2011, Google ended support of App Inventor.
Google pulled the plug on App inventor back in August, but it will live on as a MIT project. Google Research is funding the App Inventor project, and the Center for Mobile Learning is managing it at MIT. The App Inventor project was open sourced and was removed from under the umbrella of Google product. However, App Inventor has been left high and dry at present with no visible future, in spite of promises. At present, the only way to run App Inventor is to run it on the Google Apps Engine. Alternatively, you can setup your own App Inventor service using this guide.
It is interesting to note that App Inventor is based on Open Blocks, which is a MIT product itself. With untimely deaths of products like these, it is extremely demoralizing to trust a vendor and traverse up a learning curve only to find that it was all in vain. The App Inventor project will take some time, until it is back up again.