Developer website: Richard McDonald
Note: You can control the opacity or transparency of the black window that the screen saver uses to blank the screen. If you set it to transparent, you'll see the regular Mac desktop and windows while the screen saver runs. This allows you to use the launched application's output as a kind of screen saver, or to monitor its progress. This does not work if you have "require password when waking from screen saver" selected in your Security settings. If that option is selected, the screen always remains blank.
Free for your use, no warranty, use at your own risk, etc.