Http://ohbug.com/archives/delete-google-app-engine-app.html & http://xsinger.co.cc/archives/129
Google App Engine is really a good Internet application service engine. For those who love it, it provides a foundation for you to do so, for common users, you can easily create your own website on the Google App Engine Using search engine search tutorials. If you are tossing the Google App Engine and want to delete a Gae application, this article will help you.
Note: once an application is deleted, the application name with the same name cannot be applied for again.
First, go to the Gae console, http://appengine.google.com, select the Gae application instance you want to delete, and then click application settings on the Left bar,
Then you will go to the application settings editing page and move your eyes to the bottom. You will see a disable application button,
Disable it! Then you will go to the Gae instance deletion interface,
Click re-enable application now to reactivate your Gae instance. If you want to delete it completely, click the request permanent deletion button below.
After submission, you will see another similar picture,
At this time, you can still click the re-enable application now button to reactivate your Gae instance, or click revert deletion request to stop deleting and restore the Gae instance (still disabled ), if there is more than one developer for this Gae instance, other developers will receive a notification email that The Gae instance is being deleted. For example,
If a member of your development team does not want to delete the Gae instance, he/she can go to the console and discard the deletion operation.
From: http://ohbug.com/archives/delete-google-app-engine-app.html