I really like it. I've gotten a lot of great free books from there. (I guess they like Librarians). Some you have to request and others are just free to read on their app. I've been rejected for books a few times though, but only because I'm not a big enough reviewer, I think. I don't care too much for the Netgalley app, so I upload them to Kindle whenever possible, and some books you have to read immediately, because once they've been archived you can't access them anymore.

I think anyone can sign up for it though.