The idea is similar to Prezi in that you are allotted a virtual space to fill with with "slides" or photos or whatever your heart desires. Editing and adjusting how your presentation looks can take a while to master, but once you find your way around the weird radial interface, you can spit out a neat little online presentation complete with visual effects in no time at all. I'm sure that with some more experimentation, I could create something a little more attractive and with a little more pizzazz.
How does it work in the classroom?
Basically, your students can do the same types of things with ZCubes as they can do with PowerPoint or Prezi. One thing I did notice about the app was that kids were turned off by the operating interface just like I was. I usually include ZCubes as an option as opposed to a carved-in-stone requirement for little class projects.