This WAS my favorite face-swap site, and I used it extensively. Unfortunately it has been broken for several months now. The site is still there, but it no longer works, and the staff do not reply to emails.
I fear it may be gone for good, and so far I do not think any of the alternatives are as good as this one was.
If they return, I will raise the rating again, but, alas, my hopes are not high.
ETA: according to reviews further down the thread, it does appear they closed down. Such a shame. But if it had to be I wish they would have at least posted a general message to users.