Google's App Inventor is a Do-It-Yourself software for creating mobile applications.
By introducing this software Google's aim is to bring Android software development to the masses. The software is intended to make it easy for people to write applications for its Android smart phones.
The App Inventor works only for phones running Android software. It is a web-based tool. However, it requires a small software to be downloaded on to your computer. When making programs, the phone must be connected to a computer with a USB port. You will also need a Gmail account to access the tool.
The tool provides code blocks for everything. For example, you can find blocks to store information, blocks to perform actions under certain conditions, or even blocks to talk to services like Twitter, and Facebook.
Types of Applications
The tool provides access to a GPS-location sensor. So, you can build location aware and map-based applications. For example, an application to track your vehicle movement, or an application to highlight the interesting places in town.
Using this tool, you can build applications that can communicate with the phone's functionality. You can use this application to send a "love you" text message to your loved one automatically.
You can also build applications that can interact with the web using App Inventor. So, you can create applications that can interact with popular websites such as Twitter, Amazon, or Facebook.
Official link: http://appinventor.googlelabs.com/about/