Alpha to Logo filters work with the alpha channel of the active layer to add different special effects. Keep in mind that you always need an alpha channel to work with these filters.
Any Alpha to Logo filter can be added by following these steps:
The Alien Glow adds a spooky glow around the layer's alpha channel. If you apply it to a full layer maybe it doesn't add much to the image, but see what it does after a little layer duplication and reordering.
Right-click on the layer's name inside the layers widget, and select Add Alpha ...