http://www.ononesoftware.com/landing/pe8offer/
The long & short of it...
This is one part of the suite that they'd like to sell you. One of the suite's plugins is considered pretty worthwhile by many P/Shop pros, & that's their Perfect Mask -- I don't have the money so I've never used it & can't say one way of the other. The rest of the plugins AFAIK are considered by these same pros as "if you like them, great, but they don't do anything you couldn't do otherwise."
And that tells the story of the plugin they're giving away free. I've got it installed from the last time they offered it, and as a P/Shop plugin it might be useful suggesting combinations of settings that you could as easily make on your own -- the difference is that they show you large thumbnail previews, so you *may* find the look you're after sooner.
But it's also a standalone app, and *may* offer some stuff your editing software does not.
