The source code is at https://github.com/rosgen/scirate3 and the site is currently deployed at https://vivid-fog-5450.herokuapp.com/ .
If you create an account you can scite papers. If you want more than quant-ph you can 'subscribe' to multiple arXiv feeds, the result of which should be that the homepage lists all of today's papers from all of your feeds.
This should be considered some sort of beta. I will do my best to keep all of the data, but if the goal is to take scirate in new directions that may not be possible.
There are couple of caveats to my implementation:
1) All the emails (password change tokens and signup verification tokens) are currently going out from my personal gmail account. This is because it's easy to set up that way and I don't have another SMTP server handy.
2) Some of the old features are missing: there is no search, there is no admin interface to deal with spam, etc. There is also no way for a user to delete their account -- if you want to do such a thing the current interface is to send me an email.
3) The code is probably pretty ugly: I didn't know Ruby or Rails before I started.
4) The database of papers only goes back so far. There's about a month of data for quant-ph, but only a couple of days for most of the arxiv categories.
5) I'm not a very good web designer. Suggestions for how things should look are welcome.
Bill