I installed it, and played around a bit. There is an email app, and a chat app, and a social network featured right on the front-page. Seems to be very dynamic, and well designed too.
TOR is supposed to make you anonymous, but AFAIK that is not really the case. You have to be on a clean device, piggybacking off someone else's network, and have javascript disabled (making most of websites unusable), and even then there are compromised exit nodes, timing attacks, etc.
Seems like TOR is just as anonymous as Bitcoin is. Obfuscated, sure. Anonymous, not really (perhaps somewhat with very rigorous precautions).
If you are visiting a .onion site there is no exit node involved. Traffic is encrypted and inside tor all the way from you to the server hosting the hidden service ... usually you need to have some trust in the operator of the service anyway. Here for instance that they don't log all the steem-passwords ... if you trust them not log your steem-password you can probably trust them not to run attacks against your connection to try and determine your location also....
It would be awesome if a ZeroNet version could be achieved. I wondered about this for a couple of weeks already.