When you first visit the Muzy website you'll see a pop-up box asking you to sign-in with a Facebook account. If you close that box you can register for the service without using your Facebook account. You can create new posts on the Muzy website, with the Muzy iOS app, and with the Muzy Android app.
Applications for Education
Muzy's integrated image search could be used by students to create a collage of images about a place, person, or event that they're studying. Students could also use the Muzy "thoughts" app to write short blog entries.
Muzy's T.O.S. requires users to be 13 or older. There is a public gallery of posts and while I didn't see anything in appropriate when I browsed through it, I suppose that there is potential for things that you wouldn't want elementary school students to browse through.
Thanks to Jim George for sharing Muzy on Twitter.