This does what it says on the tin. A glass lens (the other ApeLabs ones are plastic) which fits on top of the ApeCan or ApeCoin to give a more traditional 10 degree uplight.
Personally, I think it's worth paying for if you're uplighting. The effect lens is great (comes as standard), but more for having a group of lights together on music mode. The diffuser filter (also comes as standard) doesn't do height at all. This lens, however, really throws the light high so for a more 'standard' uplighting effect.