The site doesn't seem legit for me. I got the following email from them after sign-up:

Thank you for signing up for EduHack!

You can really help us out by sharing with your unique URL with your friends:

http://eduhack.me?lrRef=jP0nK

You can always find out how many people you have referred

by coming back to http://eduhack.me and entering your email address again.

Thank you, The EduHack Team

e: I don't know how to quote :/