It's working okay on OS X 10.7.5, except that when you select a folder of images to use as the background, the images don't rotate like they should, the first image stays static. But you can manually change images, so it's not a big deal.
Snowflakes are completely unrealistic - they're fuzzy round blobs, and you can change the quantity and wind speed.
I'm not surprised it's been discontinued, it's a bit lame and certainly not worth the $4 asking price. Might have been worth 99¢, but I got it free from someone since it's discontinued.