I searched in the app store for this app: http://cslmedia.org/iphone/
but nothing comes up. When I click the link on the site, it says it's not available in US.

I have changed my country in itunes to japan and it stills says the same thing. How can I get this app?

That page says that there was an error in the way the app communicates with WWWJDIC. He may have pulled the app until Apple approves the new version, just so new downloaders don't get a non-functional app.