Screen savers

Hello all,
I need source code for a Photon 2.0 screen saver. I need to create a custom screen saver, and can’t find the secret formula to do so. I created a simple “Hello World” Photon app. I put this app in my /usr/photon/savers directory. When I launched savercfg, I could preview my app, but when it was time for the saver service to launch the app, it did not. Are there special hooks that need to be in a photon app that makes it a screen saver?