launch app instead of firetv screensaver

I was wondering if its someone is willing to write an xposed module that replaces android screensaver with
a lunch action on an app. That way e.g. kodi could be launched which handles in my setup the sleeping of the
firetv. It would also be use full to run e.g. the flickr app or any other non amazon picture source.

As i'm not realy into the xposed development i have no real clue where to look for the right hocking method.