@criver and coexistxx
I had the same problem - unfortunately, it was when I was in my counselor's office talking about it and I couldn't pull up the website. It's still up, but the link has moved.
try this: https://secure.infosnap.com/family/login.aspx
if it doesn't work (it might not, since you're getting there from here!), go to the UWC-USA website, go to application process, then US Applicants, then down on the timeline click the SECOND "online application" link. The first takes you to the Apply Online section of the uwc website, which doesn't have the link anymore, but the SECOND ONE (I repeat - the second one) is correct.
I had to call my dad and ask where it went, and luckily he found it. Also luckily my counselor was talking to someone else in my moment of WHERE DID IT GOOO