Yes, it's a standalone version of Boris FX Particle Illusion for free.

No, you can not bring in a video, but there is a workaround to bring in a frame I believe. I have the plugin version with another editor I use.

When you download and install it, do not forget to download the hundreds of additional emitters. Help>Download Emitters. 

I haven't personally tried to import the saved PI's, but someone reported they used it in VideoStudio Pro and Pinnacle Studio.

It's free and you can download it HERE after you register at BorisFX.

There are tons of tutorials to get you up and running quickly. And it's just plain fun!