Start developing the Layar APP following the tutorial from http://www.layar.com/documentation/browser/tutorials-tools/
In the test page by default the Layar API is set to 3.0, which will not work with the supplied tutorials.
Change the API to 5.0 to work without error.
Excellent third party tools for Layar is available at http://layar.pbworks.com/w/page/30676208/Third%20Party%20Tools%20and%20Tutorials
http://www.hoppala-agency.com/article/augmented-reality-content-platform/#more-1392
Drupal Extension for LAYAR
http://drupal.org/project/layar
Right now struggling with the customised CIW for Layar App.
I have uploaded the custom icons for the CIW as per the recommendation, but it is not showing up anywhere.(http://www.layar.com/documentation/browser/publishing-site/edit-layer/)