While App Inventor apps may lack the sophistication of Android apps coded by professional developers, they can nonetheless make use of a variety of powerful features. App Inventor provides access to GPS, accelerometer, and orientation data, telephony services like phone calls and texting, speech-to-text services, contact data, persistent storage, and Web services such as those provided by Amazon and Twitter.
Some of these services aren't for technophobes -- TinyWebDB, which stores data on the Web using Google App Engine, requires some software installation and Python text file editing. But App Inventor really does allow programming novices to create functional Android apps.
Some of the sample apps include: DroidMuni, which shows schedules for the San Francisco transit system; ParkIt, which records the location of the user's car; DrumKit, a basic beat making app and educational tool; Super Hero Game, a quiz game; and Where's Speedo, an app that allows two or more users to find each other by sending location data.
Coding in App Inventor involves moving blocks about on screen and editing their properties where appropriate. App Inventor is based on MIT's Open Blocks Java library. Google says the tool builds upon the work of Seymour Papert and the MIT Logo Group.
Papert did pioneering work in the field of computer science education and Google sees App Inventor as a tool for educators as well as those interested in easier software development.
Apple last year made much of the fact that there were far more iPhone apps available than there were apps on other mobile platforms. It still has the lead with about 200,000 apps, but the marketing value of boasting about app count has been declining as the Android app count has risen.
The number of apps available in the Android Market is almost 100,000, according to AndroLib, about ten times as many as a year ago. And with App Inventor, that number is likely to rise even faster. Mobile platform differentiation going forward will probably shift toward debates about app quality and security.
Those interested in using App Inventor are invited to sign up using their Gmail address. Google says it will be granting access in coming weeks.