Tired of parsing all the source code involved in building mobile apps? Or perhaps the approval process for Apple's App Store is getting you down. Or maybe you're an aspiring commercial developer in search of the next must-have platform to tap. If you think Android might be the one, then a new tool from Google is worth a serious look.

App Inventor, a tool under development at Google, makes building apps for Android as easy as putting together a child's jigsaw puzzle. First announced on July 31, App Inventor is a drag-and-drop environment that appears to require only the most basic knowledge of how applications work. Acting as building blocks for applications, puzzle pieces are shaped based on their functionality, and their ability to connect and interact with other components.

Now in alpha testing at a number of universities, App Inventor is expected to be available to the public sometime in 2010. In the meantime, you can learn to use it thanks to this University of San Francisco professor's tutorial. In the introduction, computer science professor David Wobler explains the six components of an Android app, which are: visual components, non-visual components, events, behaviors, event handlers and variables.

App Inventor consists of two main components, Wobler explains. The Component Designer lets you select visual components such as buttons, text boxes and the like, and non-visual components like interaction with sounds or external services. Once the visuals and non-visuals are selected, the Blocks Editor lets you tell everything how to behave and respond to input.

The tutorial introduction takes you step-by-step from installation (which you can't do yet) through to building your own small app (entering a phone number and dialing it) and downloading the resulting .apk file to your phone or Android emulator. Who knows, by this time next year, maybe you'll be among the next round of Android Challenge winners. After looking at this year's picks, that should not be terribly challenging.